5G/NR Network - NGAP/N2 Interface

NGAP / N2 Interface

NGAP is the protocol(an Application Layer Protocol) being used in the communication between between gNB and AMF as illustrated below.

What I am going to do in this note is to provide details of NG Interface and NGAP (Protocol for NG Interface). Followings are the list of the topics on this note.

Overall Protocol Stack
General Principles of NG Interface
NGAP Capabilities
NGAP Elementary Procedure
NGAP Packet Structure
NGAP Establish
NR SA Registration
UPLINK NAS TRANSPORT
DOWNLINK NAS TRANSPORT
PDU Session Resource Setup
NGAP Messages/ASN

NGSetupRequest
NGSetupResponse

UE Context Release
InitialContextSetupRequest
InitialContextSetupResponse
InitialUEMessage
UEContextModificationRequest
UEContextModificationResponse

Overall Protocol Stack

Structure of the protocol stack for this interface is illustrated as below. Overall description and requirement of NGAP specified in 38.412 (very short specification). Since NGAP packet is encapsulated by IP and SCTP which are more of generic purpose (i.e, not 3GPP only), further details are specified in various RFC documents (Refer to 38.412 to know which RFC document you have to refer to). For the details of signaling procedure over NGAP, refer to 38.413.

General Principles of NG Interface

General principles of NG Interface is described in 38.410 - 4.2 as follows :

the NG interface is open;
the NG interface supports the exchange of signalling information between the NG-RAN and 5GC;
from a logical standpoint, the NG is a point-to-point interface between an NG-RAN node and a 5GC node. A point-to-point logical interface is feasible even in the absence of a physical direct connection between the NGRAN and 5GC;
the NG interface supports control plane and user plane separation;
the NG interface separates Radio Network Layer and Transport Network Layer;
the NG interface is future proof to fulfil different new requirements and support of new services and new functions;
the NG interface is decoupled with the possible NG-RAN deployment variants;
the NG Application Protocol supports modular procedures design and uses a syntax allowing optimized encoding /decoding efficiency.

NGAP Capabilities

According to 38.410-4.4, NGAP support following capabilities :

procedures to establish, maintain and release NG-RAN part of PDU sessions;
procedures to perform intra-RAT handover and inter-RAT handover;
the separation of each UE on the protocol level for user specific signalling management;
the transfer of NAS signalling messages between UE and AMF;
mechanisms for resource reservation for packet data streams.

NGAP Elementary Procedure

Followings are the list of signaling messages (Elementary Procedure) of NGAP. There are two types of elementary procedure classified into Class 1 and Class 2. The definition of Class 1 and Class 2 is stated in 38.413 - 3.1 as follows :

Class 1: Elementary Procedures with response (success and/or failure).
Class 2: Elementary Procedures without response.

The list of NGAP Elementary procedure and corresponding signaling message is defined in 38.413-8.1 as follows.

< 38.413 v16.7- Table 8.1-1: Class 1 procedures >

Elementary Procedure	Initiating Message	Successful Outcome	Unsuccessful Outcome	Examples
Elementary Procedure	Initiating Message	Response Message	Response Message	Examples
AMF Configuration Update	AMF CONFIGURATION UPDATE	AMF CONFIGURATION UPDATE ACKNOWLEDGE	AMF CONFIGURATION UPDATE FAILURE
RAN Configuration Update	RAN CONFIGURATION UPDATE	RAN CONFIGURATION UPDATE ACKNOWLEDGE	RAN CONFIGURATION UPDATE FAILURE
Handover Cancellation	HANDOVER CANCEL	HANDOVER CANCEL ACKNOWLEDGE
Handover Preparation	HANDOVER REQUIRED	HANDOVER COMMAND	HANDOVER PREPARATION FAILURE
Handover Resource Allocation	HANDOVER REQUEST	HANDOVER REQUEST ACKNOWLEDGE	HANDOVER FAILURE
Initial Context Setup	INITIAL CONTEXT SETUP REQUEST	INITIAL CONTEXT SETUP RESPONSE	INITIAL CONTEXT SETUP FAILURE
NG Reset	NG RESET	NG RESET ACKNOWLEDGE
NG Setup	NG SETUP REQUEST	NG SETUP RESPONSE	NG SETUP FAILURE
Path Switch Request	PATH SWITCH REQUEST	PATH SWITCH REQUEST ACKNOWLEDGE	PATH SWITCH REQUEST FAILURE
PDU Session Resource Modify	PDU SESSION RESOURCE MODIFY REQUEST	PDU SESSION RESOURCE MODIFY RESPONSE
PDU Session Resource Modify Indication	PDU SESSION RESOURCE MODIFY INDICATION	PDU SESSION RESOURCE MODIFY CONFIRM
PDU Session Resource Release	PDU SESSION RESOURCE RELEASE COMMAND	PDU SESSION RESOURCE RELEASE RESPONSE
PDU Session Resource Setup	PDU SESSION RESOURCE SETUP REQUEST	PDU SESSION RESOURCE SETUP RESPONSE
UE Context Modification	UE CONTEXT MODIFICATION REQUEST	UE CONTEXT MODIFICATION RESPONSE	UE CONTEXT MODIFICATION FAILURE
UE Context Release	UE CONTEXT RELEASE COMMAND	UE CONTEXT RELEASE COMPLETE
Write-Replace Warning	WRITE-REPLACE WARNING REQUEST	WRITE-REPLACE WARNING RESPONSE
PWS Cancel	PWS CANCEL REQUEST	PWS CANCEL RESPONSE
UE Radio Capability Check	UE RADIO CAPABILITY CHECK REQUEST	UE RADIO CAPABILITY CHECK RESPONSE
UE Context Suspend	UE CONTEXT SUSPEND REQUEST	UE CONTEXT SUSPEND RESPONSE	UE CONTEXT SUSPEND FAILURE
UE Context Resume	UE CONTEXT RESUME REQUEST	UE CONTEXT RESUME RESPONSE	UE CONTEXT RESUME FAILURE
UE Radio Capability ID Mapping	UE RADIO CAPABILITY ID MAPPING REQUEST	UE RADIO CAPABILITY ID MAPPING RESPONSE

< 38.413 - v16.7 :Table 8.1-2: Class 2 procedures >

Elementary Procedure	Message	Examples
Downlink RAN Configuration Transfer	DOWNLINK RAN CONFIGURATION TRANSFER
Downlink RAN Status Transfer	DOWNLINK RAN STATUS TRANSFER
Downlink NAS Transport	DOWNLINK NAS TRANSPORT
Error Indication	ERROR INDICATION
Uplink RAN Configuration Transfer	UPLINK RAN CONFIGURATION TRANSFER
Uplink RAN Status Transfer	UPLINK RAN STATUS TRANSFER
Handover Notification	HANDOVER NOTIFY
Initial UE Message	INITIAL UE MESSAGE
NAS Non Delivery Indication	NAS NON DELIVERY INDICATION
Paging	PAGING
PDU Session Resource Notify	PDU SESSION RESOURCE NOTIFY
Reroute NAS Request	REROUTE NAS REQUEST
UE Context Release Request	UE CONTEXT RELEASE REQUEST
Uplink NAS Transport	UPLINK NAS TRANSPORT
AMF Status Indication	AMF STATUS INDICATION
PWS Restart Indication	PWS RESTART INDICATION
PWS Failure Indication	PWS FAILURE INDICATION
Downlink UE Associated NRPPa Transport	DOWNLINK UE ASSOCIATED NRPPA TRANSPORT
Uplink UE Associated NRPPa Transport	UPLINK UE ASSOCIATED NRPPA TRANSPORT
Downlink Non UE Associated NRPPa Transport	DOWNLINK NON UE ASSOCIATED NRPPA TRANSPORT
Uplink Non UE Associated NRPPa Transport	UPLINK NON UE ASSOCIATED NRPPA TRANSPORT
Trace Start	TRACE START
Trace Failure Indication	TRACE FAILURE INDICATION
Deactivate Trace	DEACTIVATE TRACE
Cell Traffic Trace	CELL TRAFFIC TRACE
Location Reporting Control	LOCATION REPORTING CONTROL
Location Reporting Failure Indication	LOCATION REPORTING FAILURE INDICATION
Location Report	LOCATION REPORT
UE TNLA Binding Release	UE TNLA BINDING RELEASE REQUEST
UE Radio Capability Info Indication	UE RADIO CAPABILITY INFO INDICATION
RRC Inactive Transition Report	RRC INACTIVE TRANSITION REPORT
Overload Start	OVERLOAD START
Overload Stop	OVERLOAD STOP
Secondary RAT Data Usage Report	SECONDARY RAT DATA USAGE REPORT
Uplink RIM Information Transfer	UPLINK RIM INFORMATION TRANSFER
Downlink RIM Information Transfer	DOWNLINK RIM INFORMATION TRANSFER
Retrieve UE Information	RETRIEVE UE INFORMATION
UE Information Transfer	UE INFORMATION TRANSFER
RAN CP Relocation Indication	RAN CP RELOCATION INDICATION
Connection Establishment Indication	CONNECTION ESTABLISHMENT INDICATION
AMF CP Relocation Indication	AMF CP RELOCATION INDICATION
Handover Success	HANDOVER SUCCESS
Uplink RAN Early Status Transfer	UPLINK RAN EARLY STATUS TRANSFER
Downlink RAN Early Status Transfer	DOWNLINK RAN EARLY STATUS TRANSFER

NGAP Packet Structure

If you take packet capture (e.g, Wireshark capture) over the interface, you would get the packet structure as below.

Following is SCTP initial setup process captured with Wireshark from Amarisoft Callbox. (a),(b),(c),(d) is the initial setup of SCTP which is explained in this note , the procedure (1)~(13) is the procedure that will be described in this note.

NGAP Establish

This procedure is to establish the signaling connection between gNB and AMF (i.e, the first connection process). This is not UE specific and this will apply to every UE that are connected to the specified AMF. This process is specified in 38.413-8.7.1. The overall procedure is simple two way handshaking as illustrated below.

< 38.413-Figure 8.7.1.2-1: NG setup: successful operation >

For the description of some important IEs in NG SETUP REQUEST and NG SETUP RESPONSE message, refer to 38.413-8.7.1.2. I think it is relatively clearly described in this specification. The IEs with the description as per 38.413 v16.7 is listed as below. Most of these IEs are optional, so you may not see all of these IEs configured in NGAP log.

NGSetupRequest

Configured TAC Indication
UE Retention Information

NGSetupResponse

IAB Supported
Backup AMF Name
GUAMI Type
RAN Node Name
Extended RAN Node Name
NB-IoT Default Paging DRX
RAT Information
Broadcast PLMN Item->NPN Support->NID
PLMN Support Item->NPN Support->NID

In most cases, AMF accept NGSetupRequest from gNB and send NGSetupReponse, but if any of the following IE does not match with what AMF expects, it would refuse the connection.

pLMNIdentity
tAC

NOTE : It seems that different AMF applies a little bit of different rules for accepting the SETUP REQUEST. For example, Amarisoft AMF is checking only on pLMNIdentity but free5GC AMF seems to check both pLMNIdentity and tAC.

Following is the message structure and requirement of NG SETUP REQUEST from 48.413-9.2.6.1

Following is the message structure and requirement of NG SETUP RESPONSE from 48.413-9.2.6.2

Followings are statements from 38.413-8.7.1.2 that are related to processing the information elements in NG SETUP REQUEST message.

If theConfigured TAC Indication IE set to "true is included for a Tracking Area contained in the Supported TA List IE in the NG SETUP REQUEST message, the AMF may take it into account to optimise NG-C signalling towards this NG-RAN node.
If theUE Retention Information IE set to ues-retained is included in the NG SETUP REQUEST message, the AMF may accept the proposal to retain the existing UE related contexts and signalling connections by including the UE Retention Information IE set to ues-retained in the NG SETUP RESPONSE message.
If theRAN Node Name IE is included in the NG SETUP REQUEST message, the AMF may use this IE as a human readable name of the NG-RAN node. If theExtended RAN Node Name IE is included in the NG SETUP REQUEST message, the AMF may use this IE as a human readable name of the NG-RAN node and shall ignore the RAN Node Name IE if also included.
If theNB-IoT Default Paging DRX IE is included in the NG SETUP REQUEST message, the AMF shall take it into account for paging.
If theRAT Information IE is included in the NG SETUP REQUEST message, the AMF shall handle this information as specified in TS 23.502.
If theNID IE within theNPN Support IE is included within a Broadcast PLMN Item IE in the NG SETUP REQUEST message, the AMF shall consider that the NG-RAN node supports the indicated S-NSSAI(s) for the corresponding tracking area code for the SNPN identified by the PLMN Identity IE and the NID IE.

Followings are statements from 38.413-8.7.1.2 that are related to processing the information elements in NG SETUP RESPONSE message.

If the UE Retention Information IE set to ues-retained is included in the NG SETUP REQUEST message, the AMF may accept the proposal to retain the existing UE related contexts and signallingconnections by including the UE Retention Information IE set to ues-retained in the NG SETUP RESPONSE message.
If the AMF supports IAB, the AMF shall include the IAB Supported IE in the NG SETUP RESPONSE message.
The AMF shall include the Backup AMF Name IE, if available, in the Served GUAMI List IE in the NG SETUP RESPONSE message. The NG-RAN node shall, if supported, consider the AMF as indicated by the Backup AMF Name IE when performing AMF reselection, as specified in TS 23.501.
If the GUAMI Type IE is included in the NG SETUP RESPONSE message, the NG-RAN node shall store the received value and use it for further AMF selection as defined in TS 23.501.
If the AMF Name IE is included in the NG SETUP RESPONSE message, the NG-RAN node may use this IE as a human readable name of the AMF. If the Extended AMF Name IE is included in the NG SETUPRESPONSE message, the NG-RAN node may use this IE as a human readable name of the AMF and shall ignore the AMF Name IE if also included.
If the NID IE within the NPN Support IE is included within a PLMN Support Item IE in the NG SETUP RESPONSE message, the NG-RAN node shall consider that the AMF supports the SNPN identified by the PLMN Identity IE and the NID IE.

(1) NG Setup Request

This is the NGAP-PDU initiatingMessage with NGSetupRequest. The procedureCode is id-NGSetup (21) indicating that the procedure being initiated is the NG Setup. The criticality field in each ProtocolIE-Field indicates how the receiver should treat the IE if it is not understood; for instance, reject means the message should be rejected if the IE is not understood, while ignore means the message should still be processed.

This NG Setup process is essential for managing the gNodeB's connectivity to the network, enabling it to serve UEs within its coverage area. Once the setup request is processed and accepted by the core network, it responds with an NGSetupResponse, confirming the gNodeB is ready to handle 5G communications..

NGSetupRequest: The gNodeB uses this message to establish initial context with the core network. It contains several Information Elements (IEs), each with an id, criticality, and value, providing specific details about the gNodeB and its capabilities.

GlobalRANNodeID: Included in the request to uniquely identify the gNodeB globally within the 5G network using a PLMN Identity and a gNB ID.
RANNodeName: A human-readable name assigned to the gNodeB for easier identification, likely used during operational and management tasks.
SupportedTAList: Lists the Tracking Areas that the gNodeB supports, which are crucial for paging and mobility management of UEs when they are not in active communication with the network.
DefaultPagingDRX: Defines the default Discontinuous Reception (DRX) cycle for the gNodeB, a power-saving feature that dictates how frequently a UE in idle mode should listen for paging messages.

Internet Protocol Version 4, Src: 10.0.0.185, Dst: 10.0.0.162

0100 .... = Version: 4

.... 0101 = Header Length: 20 bytes (5)

Differentiated Services Field: 0x02 (DSCP: CS0, ECN: ECT(0))

0000 00.. = Differentiated Services Codepoint: Default (0)

.... ..10 = Explicit Congestion Notification: ECN-Capable Transport codepoint '10' (2)

Total Length: 108

Identification: 0x0001 (1)

Flags: 0x40, Don't fragment

0... .... = Reserved bit: Not set

.1.. .... = Don't fragment: Set

..0. .... = More fragments: Not set

Fragment Offset: 0

Time to Live: 64

Protocol: SCTP (132)

Header Checksum: 0x24b1 [validation disabled]

[Header checksum status: Unverified]

Source Address: 10.0.0.185

Destination Address: 10.0.0.162

Stream Control Transmission Protocol, Src Port: 48041 (48041), Dst Port: 38412 (38412)

Source port: 48041

Destination port: 38412

Verification tag: 0x790ad620

[Association index: 65535]

Checksum: 0x3dba6023 [unverified]

[Checksum Status: Unverified]

DATA chunk(ordered, complete segment, TSN: 3757580128, SID: 0, SSN: 0, PPID: 60,

payload length: 58 bytes)

Chunk type: DATA (0)

0... .... = Bit: Stop processing of the packet

.0.. .... = Bit: Do not report

Chunk flags: 0x03

.... 0... = I-Bit: Possibly delay SACK

.... .0.. = U-Bit: Ordered delivery

.... ..1. = B-Bit: First segment

.... ...1 = E-Bit: Last segment

Chunk length: 74

Transmission sequence number: 3757580128

[This chunk is acked in frame: 138]

[The RTT to SACK was: 0.000032008 seconds]

Stream identifier: 0x0000

Stream sequence number: 0

Payload protocol identifier: NGAP (60)

Chunk padding: 0000

NG Application Protocol

NGAP-PDU: initiatingMessage (0)

initiatingMessage

procedureCode: id-NGSetup (21)

criticality: reject (0)

value

NGSetupRequest

protocolIEs: 4 items

Item 0: id-GlobalRANNodeID

ProtocolIE-Field

id: id-GlobalRANNodeID (27)

criticality: reject (0)

value

GlobalRANNodeID: globalGNB-ID (0)

globalGNB-ID

pLMNIdentity: 00f110

Mobile Country Code (MCC): Unknown (1)

Mobile Network Code (MNC): Unknown (01)

gNB-ID: gNB-ID (0)

gNB-ID: 00123450 [bit length 28, 4 LSB pad bits,

....]

Item 1: id-RANNodeName

ProtocolIE-Field

id: id-RANNodeName (82)

criticality: ignore (1)

value

RANNodeName: gnb0012345

Item 2: id-SupportedTAList

ProtocolIE-Field

id: id-SupportedTAList (102)

criticality: reject (0)

value

SupportedTAList: 1 item

Item 0

SupportedTAItem

tAC: 100 (0x000064)

broadcastPLMNList: 1 item

Item 0

BroadcastPLMNItem

pLMNIdentity: 00f110

Mobile Country Code (MCC):

Unknown (1)

Mobile Network Code (MNC):

Unknown (01)

tAISliceSupportList: 1 item

Item 0

SliceSupportItem

s-NSSAI

sST: 01

Item 3: id-DefaultPagingDRX

ProtocolIE-Field

id: id-DefaultPagingDRX (21)

criticality: ignore (1)

value

PagingDRX: v128 (2)

(2) NG Setup Response

This is a NGSetupResponse message within the NGAP (Next Generation Application Protocol) for 5G systems. This message is part of the signaling between the 5G gNodeB (base station) and the core network, particularly the AMF (Access and Mobility Management Function). It is categorized as a successfulOutcome, indicating a successful completion of the NG Setup procedure that was initiated by a NGSetupRequest.

Here is the breakdown of the NGSetupResponse message:

id-AMFName (Item 0): This field contains the name of the AMF, amarisoft.amf.5gc.mnc001.mcc001.3gppnetwork.org. The AMF Name is used for identification and usually follows a domain name structure.
id-ServedGUAMIList (Item 1): This field lists the GUAMI (Globally Unique AMF ID) served by the AMF. The GUAMI includes the PLMN Identity, AMF Region ID, AMF Set ID, and AMF Pointer, which together uniquely identify the AMF within the global 5G network.
id-RelativeAMFCapacity (Item 2): This indicates the relative capacity of the AMF, which is a dimensionless value that allows for load balancing and priority handling among different AMFs.
id-PLMNSupportList (Item 3): This lists the PLMNs (Public Land Mobile Networks) that the AMF supports, along with the slices available for each PLMN. The slice support is indicated by the s-NSSAI (Single Network Slice Selection Assistance Information), which identifies the slice(s) supported.

Each ProtocolIE-Field is composed of an id, criticality, and value. The criticality of reject indicates that the receiving entity should reject the message and potentially notify the sender if it does not understand the IE, whereas ignore indicates that the message should be processed normally even if the IE is not understood

Internet Protocol Version 4, Src: 10.0.0.162, Dst: 10.0.0.185

0100 .... = Version: 4

.... 0101 = Header Length: 20 bytes (5)

Differentiated Services Field: 0x02 (DSCP: CS0, ECN: ECT(0))

0000 00.. = Differentiated Services Codepoint: Default (0)

.... ..10 = Explicit Congestion Notification: ECN-Capable Transport codepoint '10' (2)

Total Length: 140

Identification: 0xadd1 (44497)

Flags: 0x40, Don't fragment

0... .... = Reserved bit: Not set

.1.. .... = Don't fragment: Set

..0. .... = More fragments: Not set

Fragment Offset: 0

Time to Live: 64

Protocol: SCTP (132)

Header Checksum: 0x76c0 [validation disabled]

[Header checksum status: Unverified]

Source Address: 10.0.0.162

Destination Address: 10.0.0.185

Stream Control Transmission Protocol, Src Port: 38412 (38412), Dst Port: 48041 (48041)

Source port: 38412

Destination port: 48041

Verification tag: 0x8d10a6cf

[Association index: 65535]

Checksum: 0x5a3ac41a [unverified]

[Checksum Status: Unverified]

DATA chunk(ordered, complete segment, TSN: 4169966867, SID: 0, SSN: 0, PPID: 60,

payload length: 89 bytes)

Chunk type: DATA (0)

0... .... = Bit: Stop processing of the packet

.0.. .... = Bit: Do not report

Chunk flags: 0x03

.... 0... = I-Bit: Possibly delay SACK

.... .0.. = U-Bit: Ordered delivery

.... ..1. = B-Bit: First segment

.... ...1 = E-Bit: Last segment

Chunk length: 105

Transmission sequence number: 4169966867

[This chunk is acked in frame: 140]

[The RTT to SACK was: 0.004556150 seconds]

Stream identifier: 0x0000

Stream sequence number: 0

Payload protocol identifier: NGAP (60)

Chunk padding: 000000

NG Application Protocol

NGAP-PDU: successfulOutcome (1)

successfulOutcome

procedureCode: id-NGSetup (21)

criticality: reject (0)

value

NGSetupResponse

protocolIEs: 4 items

Item 0: id-AMFName

ProtocolIE-Field

id: id-AMFName (1)

criticality: reject (0)

value

AMFName: amarisoft.amf.5gc.mnc001.mcc001.3gppnetwork.org

Item 1: id-ServedGUAMIList

ProtocolIE-Field

id: id-ServedGUAMIList (96)

criticality: reject (0)

value

ServedGUAMIList: 1 item

Item 0

ServedGUAMIItem

gUAMI

pLMNIdentity: 00f110

Mobile Country Code (MCC): Unknown (1)

Mobile Network Code (MNC): Unknown (01)

aMFRegionID: 80 [bit length 8,

1000 0000 decimal value 128]

aMFSetID: 0100 [bit length 10,

6 LSB pad bits, 0000 0001 00.. ....

decimal value 4]

aMFPointer: 04 [bit length 6, 2 LSB pad bits,

0000 01.. decimal value 1]

Item 2: id-RelativeAMFCapacity

ProtocolIE-Field

id: id-RelativeAMFCapacity (86)

criticality: ignore (1)

value

RelativeAMFCapacity: 50

Item 3: id-PLMNSupportList

ProtocolIE-Field

id: id-PLMNSupportList (80)

criticality: reject (0)

value

PLMNSupportList: 1 item

Item 0

PLMNSupportItem

pLMNIdentity: 00f110

Mobile Country Code (MCC): Unknown (1)

Mobile Network Code (MNC): Unknown (01)

sliceSupportList: 1 item

Item 0

SliceSupportItem

s-NSSAI

sST: 01

NR SA Registration

The Initial UE Message procedure is used when the NG-RAN node has received from the radio interface the first uplink NAS message to be forwarded to an AMF.

< 38.413-Figure 8.6.1.2-1: Initial UE message >

Following is from 38.413 - 9.2.5.1 about the message structure and requirement for INITIAL UE MESSAGE.

Followings are statements from 38.413-8.6.1.2 that are related to processing the information elements in this message.

The NG-RAN node initiates the procedure by sending an INITIAL UE MESSAGE message to the AMF. The NG-RAN node shall allocate a uniqueRAN UE NGAP ID to be used for the UE and the NG-RAN node shall include this identity in the INITIAL UE MESSAGE message.
The NAS-PDU IE contains a UE AMF message that is transferred without interpretation in the NG-RAN node.
In case of network sharing, the selected PLMN is indicated by the PLMN Identity IE within theTAI IE included in the INITIAL UE MESSAGE message.
When the NG-RAN node has received from the radio interface the5G-S-TMSI IE, it shall include it in the INITIAL UE MESSAGE message.
If theAMF Set ID IE is included in the INITIAL UE MESSAGE message this indicates that the message is a rerouted message and the AMF shall, if supported, use the IE as described in TS 23.502.
If theUE Context Request IE is included in the INITIAL UE MESSAGE message the AMF shall trigger an Initial Context Setup procedure towards the NG-RAN node.
If theAllowed NSSAI IE is included in the INITIAL UE MESSAGE message the AMF shall use the IE as defined in TS 23.502.
If the Source toTarget AMF Information Reroute IE is included in the INITIAL UE MESSAGE message the AMF shall use the IE as defined in TS 23.502.
If theIAB Node Indication IE is included in the INITIAL UE MESSAGE message, the AMF shall consider that the message is related to an IAB node.
If theCE-mode-B Support Indicator IE is included in the INITIAL UE MESSAGE message and set to "supported", the AMF shall, if supported, use the extended NAS timer settings for the UE as specified in TS 23.501.
If theLTE-M indication IE is included in the INITIAL UE MESSAGE message the AMF shall, if supported, use it according to TS 23.501.
If theEDT Session IE set to "true" is included in the INITIAL UE MESSAGE message and the NG-RAN node is an ngeNB,the AMF shall, if supported, consider that the message has been received as a result of an EDT session initiated by the UE.
If PNI-NPN related information within theNPN Access Information IE is received in the INITIAL UE MESSAGE message, the AMF shall, if supported, consider that the included information is associated to the cell via which the UE has sent the first NAS message, and to the PLMN Identity which is indicated within theTAI IE, and use the included information as specified in TS 23.501.
In case of network sharing for SNPNs, the selected SNPN is indicated within theUser Location Information IE included in the INITIAL UE MESSAGE message by thePLMN Identity IE within theTAI IE and theNID IE.

(3) InitialUEMessage

This is InitialUEMessage NGAP PDU which is an initiating message sent from a User Equipment (UE) to the 5G core network through the gNodeB. It is used to establish initial contact with the network and to carry the first NAS (Non-Access Stratum) message from the UE. The InitialUEMessage is critical for the UE to communicate its presence and to begin the necessary procedures for service within the 5G network, such as registration or a service request. The NAS PDU carries essential security and capability information that the network needs to authenticate the UE and provide the appropriate services.

This message is part of the 5G NR signaling process and contains multiple information elements (IEs) that serve different purposes:

id-RAN-UE-NGAP-ID (Item 0) : This IE carries an identifier assigned by the RAN to the UE for the purposes of NGAP signaling.
id-NAS-PDU (Item 1) :: This IE contains the NAS message that is typically used for procedures like registration, service request, or paging response. The NAS PDU included in this example is a 'Registration Request' with detailed information about the UE's capabilities and the requested services.
id-UserLocationInformation (Item 2) :: Provides the location information of the UE, including the NR (New Radio) cell identifier and the tracking area identifier.
id-RRCEstablishmentCause (Item 3) :: Indicates the reason why the RRC (Radio Resource Control) connection was established, which in this case is for 'mo-Signalling' (mobile originating signaling).
id-UEContextRequest (Item 4) :: Indicates whether the UE is requesting the setup of an NGAP context. A value of 'requested' indicates that the UE requests the establishment of context.

Internet Protocol Version 4, Src: 10.0.0.185, Dst: 10.0.0.162

0100 .... = Version: 4

.... 0101 = Header Length: 20 bytes (5)

Differentiated Services Field: 0x02 (DSCP: CS0, ECN: ECT(0))

0000 00.. = Differentiated Services Codepoint: Default (0)

.... ..10 = Explicit Congestion Notification: ECN-Capable Transport codepoint '10' (2)

Total Length: 188

Identification: 0x0009 (9)

Flags: 0x40, Don't fragment

0... .... = Reserved bit: Not set

.1.. .... = Don't fragment: Set

..0. .... = More fragments: Not set

Fragment Offset: 0

Time to Live: 64

Protocol: SCTP (132)

Header Checksum: 0x2459 [validation disabled]

[Header checksum status: Unverified]

Source Address: 10.0.0.185

Destination Address: 10.0.0.162

Stream Control Transmission Protocol, Src Port: 48041 (48041), Dst Port: 38412 (38412)

Source port: 48041

Destination port: 38412

Verification tag: 0x790ad620

[Association index: 65535]

Checksum: 0xdd43ee10 [unverified]

[Checksum Status: Unverified]

DATA chunk(ordered, complete segment, TSN: 3757580129, SID: 1, SSN: 0, PPID: 60,

payload length: 137 bytes)

Chunk type: DATA (0)

0... .... = Bit: Stop processing of the packet

.0.. .... = Bit: Do not report

Chunk flags: 0x03

.... 0... = I-Bit: Possibly delay SACK

.... .0.. = U-Bit: Ordered delivery

.... ..1. = B-Bit: First segment

.... ...1 = E-Bit: Last segment

Chunk length: 153

Transmission sequence number: 3757580129

[This chunk is acked in frame: 886]

[The RTT to SACK was: 0.000119970 seconds]

Stream identifier: 0x0001

Stream sequence number: 0

Payload protocol identifier: NGAP (60)

Chunk padding: 000000

NG Application Protocol

NGAP-PDU: initiatingMessage (0)

initiatingMessage

procedureCode: id-InitialUEMessage (15)

criticality: ignore (1)

value

InitialUEMessage

protocolIEs: 5 items

Item 0: id-RAN-UE-NGAP-ID

ProtocolIE-Field

id: id-RAN-UE-NGAP-ID (85)

criticality: reject (0)

value

RAN-UE-NGAP-ID: 1

Item 1: id-NAS-PDU

ProtocolIE-Field

id: id-NAS-PDU (38)

criticality: reject (0)

value

NAS-PDU: 7e017d335df8077e004109000bf200f110...

Non-Access-Stratum 5GS (NAS)PDU

Security protected NAS 5GS message

Extended protocol discriminator:

5G mobility management messages (126)

0000 .... = Spare Half Octet: 0

.... 0001 = Security header type:

Integrity protected (1)

Message authentication code: 0x7d335df8

Sequence number: 7

Plain NAS 5GS Message

Extended protocol discriminator:

5G mobility management messages (126)

0000 .... = Spare Half Octet: 0

.... 0000 = Security header type:

Plain NAS message, not security protected (0)

Message type: Registration request (0x41)

5GS registration type

.... 1... = Follow-On Request bit (FOR):

Follow-on request pending

.... .001 = 5GS registration type:

initial registration (1)

NAS key set identifier

0... .... = Type of security context flag(TSC):

Native security context (for KSIAMF)

.000 .... = NAS key set identifier: 0

5GS mobile identity

Length: 11

.... 0... = Odd/even indication:

Even number of identity digits

.... .010 = Type of identity: 5G-GUTI (2)

Mobile Country Code (MCC): Unknown (1)

Mobile Network Code (MNC): Unknown (01)

AMF Region ID: 128

0000 0001 00.. .... = AMF Set ID: 4

..00 0001 = AMF Pointer: 1

5G-TMSI: 3776478432 (0xe1187ce0)

UE security capability

Element ID: 0x2e

Length: 4

1... .... = 5G-EA0: Supported

.1.. .... = 128-5G-EA1: Supported

..1. .... = 128-5G-EA2: Supported

...1 .... = 128-5G-EA3: Supported

.... 0... = 5G-EA4: Not supported

.... .0.. = 5G-EA5: Not supported

.... ..0. = 5G-EA6: Not supported

.... ...0 = 5G-EA7: Not supported

0... .... = 5G-IA0: Not supported

.1.. .... = 128-5G-IA1: Supported

..1. .... = 128-5G-IA2: Supported

...1 .... = 128-5G-IA3: Supported

.... 0... = 5G-IA4: Not supported

.... .0.. = 5G-IA5: Not supported

.... ..0. = 5G-IA6: Not supported

.... ...0 = 5G-IA7: Not supported

1... .... = EEA0: Supported

.1.. .... = 128-EEA1: Supported

..1. .... = 128-EEA2: Supported

...1 .... = 128-EEA3: Supported

.... 0... = EEA4: Not supported

.... .0.. = EEA5: Not supported

.... ..0. = EEA6: Not supported

.... ...0 = EEA7: Not supported

0... .... = EIA0: Not supported

.1.. .... = 128-EIA1: Supported

..1. .... = 128-EIA2: Supported

...1 .... = 128-EIA3: Supported

.... 0... = EIA4: Not supported

.... .0.. = EIA5: Not supported

.... ..0. = EIA6: Not supported

.... ...0 = EIA7: Not supported

NAS message container

Element ID: 0x71

Length: 56

Non-Access-Stratum 5GS (NAS)PDU

Plain NAS 5GS Message

Extended protocol discriminator:

5G mobility management messages (126)

0000 .... = Spare Half Octet: 0

.... 0000 = Security header type:

Plain NAS message,

not security protected (0)

Message type:

Registration request (0x41)

5GS registration type

.... 1... = Follow-On Request bit

(FOR): Follow-on request pending

.... .001 = 5GS registration type:

initial registration (1)

NAS key set identifier

0... .... =

Type of security context flag(TSC)

: Native security context

(for KSIAMF)

.000 ....=NAS key set identifier:0

5GS mobile identity

Length: 11

.... 0... = Odd/even indication:

Even number of identity digits

.... .010 = Type of identity:

5G-GUTI (2)

Mobile Country Code (MCC):

Unknown (1)

Mobile Network Code (MNC):

Unknown (01)

AMF Region ID: 128

0000 0001 00.. .... = AMF Set ID: 4

..00 0001 = AMF Pointer: 1

5G-TMSI: 3776478432 (0xe1187ce0)

5GMM capability

Element ID: 0x10

Length: 1

0... .... = Spare: 0

.0.. .... = Spare: 0

..0. .... = Spare: 0

...0 .... = Spare: 0

.... 0... = Spare: 0

.... .0.. = LTE PositioningProtocol

(LPP) capability: Not Requested

.... ..1. = HO attach: Supported

.... ...1 = S1 mode: Requested

UE security capability

Element ID: 0x2e

Length: 4

1... .... = 5G-EA0: Supported

.1.. .... = 128-5G-EA1: Supported

..1. .... = 128-5G-EA2: Supported

...1 .... = 128-5G-EA3: Supported

.... 0... = 5G-EA4: Not supported

.... .0.. = 5G-EA5: Not supported

.... ..0. = 5G-EA6: Not supported

.... ...0 = 5G-EA7: Not supported

0... .... = 5G-IA0: Not supported

.1.. .... = 128-5G-IA1: Supported

..1. .... = 128-5G-IA2: Supported

...1 .... = 128-5G-IA3: Supported

.... 0... = 5G-IA4: Not supported

.... .0.. = 5G-IA5: Not supported

.... ..0. = 5G-IA6: Not supported

.... ...0 = 5G-IA7: Not supported

1... .... = EEA0: Supported

.1.. .... = 128-EEA1: Supported

..1. .... = 128-EEA2: Supported

...1 .... = 128-EEA3: Supported

.... 0... = EEA4: Not supported

.... .0.. = EEA5: Not supported

.... ..0. = EEA6: Not supported

.... ...0 = EEA7: Not supported

0... .... = EIA0: Not supported

.1.. .... = 128-EIA1: Supported

..1. .... = 128-EIA2: Supported

...1 .... = 128-EIA3: Supported

.... 0... = EIA4: Not supported

.... .0.. = EIA5: Not supported

.... ..0. = EIA6: Not supported

.... ...0 = EIA7: Not supported

NSSAI - Requested NSSAI

Element ID: 0x2f

Length: 2

S-NSSAI 1

Length: 1

Slice/service type (SST): 1

5GS tracking area identity -

Last visited registered TAI

Element ID: 0x52

Mobile Country Code (MCC):

Unknown (1)

Mobile Network Code (MNC):

Unknown (01)

TAC: 100

UE network capability

Element ID: 0x17

Length: 7

1... .... = EEA0: Supported

.1.. .... = 128-EEA1: Supported

..1. .... = 128-EEA2: Supported

...1 .... = 128-EEA3: Supported

.... 0... = EEA4: Not supported

.... .0.. = EEA5: Not supported

.... ..0. = EEA6: Not supported

.... ...0 = EEA7: Not supported

0... .... = EIA0: Not supported

.1.. .... = 128-EIA1: Supported

..1. .... = 128-EIA2: Supported

...1 .... = 128-EIA3: Supported

.... 0... = EIA4: Not supported

.... .0.. = EIA5: Not supported

.... ..0. = EIA6: Not supported

.... ...0 = EIA7: Not supported

1... .... = UEA0: Supported

.1.. .... = UEA1: Supported

..0. .... = UEA2: Not supported

...0 .... = UEA3: Not supported

.... 0... = UEA4: Not supported

.... .0.. = UEA5: Not supported

.... ..0. = UEA6: Not supported

.... ...0 = UEA7: Not supported

0... .... = UCS2 support (UCS2):

The UE has a preference

for the default alphabet

.1.. .... = UIA1: Supported

..0. .... = UIA2: Not supported

...0 .... = UIA3: Not supported

.... 0... = UIA4: Not supported

.... .0.. = UIA5: Not supported

.... ..0. = UIA6: Not supported

.... ...0 = UIA7: Not supported

0... .... = ProSe direct discovery:

Not supported

.0.. .... = ProSe: Not supported

..0. .... = H.245 After SRVCC

Handover: Not supported

...1 .... = Access class control

for CSFB: Supported

.... 1... = LTE Positioning

Protocol: Supported

.... .0.. = Location services (LCS)

notification mechanisms:

Not supported

.... ..0. = SRVCC from E-UTRAN to

cdma2000 1xCS: Not supported

.... ...1 = Notification procedure:

Supported

1... .... = Extended protocol

configuration options: Supported

.0.. .... = Header compression

for control plane CIoT EPS

optimization: Not supported

..0. .... = EMM-REGISTERED w/o

PDN connectivity: Not supported

...0 .... = S1-U data transfer:

Not supported

.... 0... = User plane CIoT EPS

optimization: Not supported

.... .0.. = Control plane CIoT EPS

optimization: Not supported

.... ..0. = ProSe UE-to-network

relay: Not supported

.... ...0 = ProSe direct

communication: Not supported

1... .... = Signalling for a max number of 15 EPS bearer

contexts: Supported

.0.. .... = Service gap control:

Not supported

..1. .... = N1 mode: Supported

...1 .... = Dual connectivity

with NR: Supported

.... 0... = Control plane data

backoff: Not supported

.... .0.. = Restriction on use of

enhanced coverage:Not supported

.... ..0. = V2X communication over

PC5: Not supported

.... ...0 = Multiple DRB:

Not supported

UE's usage setting

Element ID: 0x18

Length: 1

.... 0... = Spare: 0

.... .0.. = Spare: 0

.... ..0. = Spare: 0

.... ...1 = UE's usage setting:

Data centric

LADN indication

Element ID: 0x74

Length: 0

Network slicing indication

1001 .... = Element ID: 0x9-

.... 0... = Spare: 0

.... .0.. = Spare: 0

.... ..0. = Default configuredNSSAI

indication (DCNI): Requested

NSSAI not created from default

configured NSSAI

.... ...0 = Network slicing

subscription change indication

(NSSCI): Not Changed

5GS update type

Element ID: 0x53

Length: 1

.... 0... = Spare: 0

.... .0.. = Spare: 0

.... ..0. = NG-RAN Radio Capability

Update (NG-RAN-RCU): Not Needed

.... ...1 = SMS requested: SMS over

NAS supported

Item 2: id-UserLocationInformation

ProtocolIE-Field

id: id-UserLocationInformation (121)

criticality: reject (0)

value

UserLocationInformation: userLocationInformationNR (1)

userLocationInformationNR

nR-CGI

pLMNIdentity: 00f110

Mobile Country Code (MCC): Unknown (1)

Mobile Network Code (MNC): Unknown (01)

nRCellIdentity: 0x0001234501

tAI

pLMNIdentity: 00f110

Mobile Country Code (MCC): Unknown (1)

Mobile Network Code (MNC): Unknown (01)

tAC: 100 (0x000064)

Item 3: id-RRCEstablishmentCause

ProtocolIE-Field

id: id-RRCEstablishmentCause (90)

criticality: ignore (1)

value

RRCEstablishmentCause: mo-Signalling (3)

Item 4: id-UEContextRequest

ProtocolIE-Field

id: id-UEContextRequest (112)

criticality: ignore (1)

value

UEContextRequest: requested (0)

(4) DownlinkNasTransport

This is DownlinkNASTransport message which carries NAS Security Mode Command message.

The message contains three main information elements (IEs):

id-AMF-UE-NGAP-ID (Item 0): This is a unique identifier assigned by the AMF to the UE for NGAP signaling purposes. In this case, it is set to 102.
id-RAN-UE-NGAP-ID (Item 1):: This is the identifier assigned by the RAN (Radio Access Network) to the UE within the context of NGAP signaling. The identifier is 1 in this instance.
id-NAS-PDU (Item 2):: This carries the actual NAS message. The NAS PDU provided is a Security Mode Command message, which is used to command the UE to use specific security algorithms for encryption and integrity protection. The message indicates the selected ciphering algorithm (5G-EA0 which is null ciphering) and the selected integrity protection algorithm (128-5G-IA2). It also relays the UE's security capabilities, which include support for various encryption and integrity protection algorithms. Additionally, the NAS PDU requests the IMEISV (International Mobile Equipment Identity Software Version), a unique identifier for the mobile device.

Internet Protocol Version 4, Src: 10.0.0.162, Dst: 10.0.0.185

0100 .... = Version: 4

.... 0101 = Header Length: 20 bytes (5)

Differentiated Services Field: 0x02 (DSCP: CS0, ECN: ECT(0))

0000 00.. = Differentiated Services Codepoint: Default (0)

.... ..10 = Explicit Congestion Notification: ECN-Capable Transport codepoint '10' (2)

Total Length: 116

Identification: 0xadd8 (44504)

Flags: 0x40, Don't fragment

0... .... = Reserved bit: Not set

.1.. .... = Don't fragment: Set

..0. .... = More fragments: Not set

Fragment Offset: 0

Time to Live: 64

Protocol: SCTP (132)

Header Checksum: 0x76d1 [validation disabled]

[Header checksum status: Unverified]

Source Address: 10.0.0.162

Destination Address: 10.0.0.185

Stream Control Transmission Protocol, Src Port: 38412 (38412), Dst Port: 48041 (48041)

Source port: 38412

Destination port: 48041

Verification tag: 0x8d10a6cf

[Association index: 65535]

Checksum: 0xe5d8cd9f [unverified]

[Checksum Status: Unverified]

SACK chunk (Cumulative TSN: 3757580129, a_rwnd: 106496, gaps: 0, duplicate TSNs: 0)

Chunk type: SACK (3)

0... .... = Bit: Stop processing of the packet

.0.. .... = Bit: Do not report

Chunk flags: 0x00

.... ...0 = Nounce sum: 0

Chunk length: 16

Cumulative TSN ACK: 3757580129

[Acknowledges TSN: 3757580129]

[Acknowledges TSN in frame: 885]

[The RTT since DATA was: 0.000119970 seconds]

Advertised receiver window credit (a_rwnd): 106496

Number of gap acknowledgement blocks: 0

Number of duplicated TSNs: 0

DATA chunk(ordered, complete segment, TSN: 4169966868, SID: 1, SSN: 0, PPID: 60,

payload length: 50 bytes)

Chunk type: DATA (0)

0... .... = Bit: Stop processing of the packet

.0.. .... = Bit: Do not report

Chunk flags: 0x03

.... 0... = I-Bit: Possibly delay SACK

.... .0.. = U-Bit: Ordered delivery

.... ..1. = B-Bit: First segment

.... ...1 = E-Bit: Last segment

Chunk length: 66

Transmission sequence number: 4169966868

[This chunk is acked in frame: 893]

[The RTT to SACK was: 0.046143403 seconds]

Stream identifier: 0x0001

Stream sequence number: 0

Payload protocol identifier: NGAP (60)

Chunk padding: 0000

NG Application Protocol

NGAP-PDU: initiatingMessage (0)

initiatingMessage

procedureCode: id-DownlinkNASTransport (4)

criticality: ignore (1)

value

DownlinkNASTransport

protocolIEs: 3 items

Item 0: id-AMF-UE-NGAP-ID

ProtocolIE-Field

id: id-AMF-UE-NGAP-ID (10)

criticality: reject (0)

value

AMF-UE-NGAP-ID: 102

Item 1: id-RAN-UE-NGAP-ID

ProtocolIE-Field

id: id-RAN-UE-NGAP-ID (85)

criticality: reject (0)

value

RAN-UE-NGAP-ID: 1

Item 2: id-NAS-PDU

ProtocolIE-Field

id: id-NAS-PDU (38)

criticality: reject (0)

value

NAS-PDU: 7e034cd87aa9067e005d020004f070f070e157021904f070c040

Non-Access-Stratum 5GS (NAS)PDU

Security protected NAS 5GS message

Extended protocol discriminator:

5G mobility management messages (126)

0000 .... = Spare Half Octet: 0

.... 0011 = Security header type:

Integrity protected

with new 5GS security context (3)

Message authentication code: 0x4cd87aa9

Sequence number: 6

Plain NAS 5GS Message

Extended protocol discriminator:

5G mobility management messages (126)

0000 .... = Spare Half Octet: 0

.... 0000 = Security header type:

Plain NAS message, not security protected (0)

Message type: Security mode command (0x5d)

NAS security algorithms

0000 .... = Type of ciphering algorithm:

5G-EA0 (null ciphering algorithm) (0)

.... 0010 = Type of integrity protection

algorithm: 128-5G-IA2 (2)

0000 .... = Spare Half Octet: 0

NAS key set identifier - ngKSI

.... 0... = Type of security context flag(TSC):

Native security context (for KSIAMF)

.... .000 = NAS key set identifier: 0

UE security capability -

Replayed UE security capabilities

Length: 4

1... .... = 5G-EA0: Supported

.1.. .... = 128-5G-EA1: Supported

..1. .... = 128-5G-EA2: Supported

...1 .... = 128-5G-EA3: Supported

.... 0... = 5G-EA4: Not supported

.... .0.. = 5G-EA5: Not supported

.... ..0. = 5G-EA6: Not supported

.... ...0 = 5G-EA7: Not supported

0... .... = 5G-IA0: Not supported

.1.. .... = 128-5G-IA1: Supported

..1. .... = 128-5G-IA2: Supported

...1 .... = 128-5G-IA3: Supported

.... 0... = 5G-IA4: Not supported

.... .0.. = 5G-IA5: Not supported

.... ..0. = 5G-IA6: Not supported

.... ...0 = 5G-IA7: Not supported

1... .... = EEA0: Supported

.1.. .... = 128-EEA1: Supported

..1. .... = 128-EEA2: Supported

...1 .... = 128-EEA3: Supported

.... 0... = EEA4: Not supported

.... .0.. = EEA5: Not supported

.... ..0. = EEA6: Not supported

.... ...0 = EEA7: Not supported

0... .... = EIA0: Not supported

.1.. .... = 128-EIA1: Supported

..1. .... = 128-EIA2: Supported

...1 .... = 128-EIA3: Supported

.... 0... = EIA4: Not supported

.... .0.. = EIA5: Not supported

.... ..0. = EIA6: Not supported

.... ...0 = EIA7: Not supported

IMEISV request

1110 .... = Element ID: 0xe-

.... 0... = Spare bit(s): 0x00

.... .001 = IMEISV request: IMEISV requested(1)

NAS security algorithms - Selected EPS NAS

security algorithms

Element ID: 0x57

0... .... = Spare bit(s): 0x00

.000 .... = Type of ciphering algorithm:

EPS encryption algorithm EEA0

.... 0... = Spare bit(s): 0x00

.... .010 = Type of integrity protection

algorithm: EPS integrity algorithm 128-EIA2

UE security capability -

Replayed S1 UE security capabilities

Element ID: 0x19

Length: 4

1... .... = EEA0: Supported

.1.. .... = 128-EEA1: Supported

..1. .... = 128-EEA2: Supported

...1 .... = 128-EEA3: Supported

.... 0... = EEA4: Not supported

.... .0.. = EEA5: Not supported

.... ..0. = EEA6: Not supported

.... ...0 = EEA7: Not supported

0... .... = EIA0: Not supported

.1.. .... = 128-EIA1: Supported

..1. .... = 128-EIA2: Supported

...1 .... = 128-EIA3: Supported

.... 0... = EIA4: Not supported

.... .0.. = EIA5: Not supported

.... ..0. = EIA6: Not supported

.... ...0 = EIA7: Not supported

1... .... = UEA0: Supported

.1.. .... = UEA1: Supported

..0. .... = UEA2: Not supported

...0 .... = UEA3: Not supported

.... 0... = UEA4: Not supported

.... .0.. = UEA5: Not supported

.... ..0. = UEA6: Not supported

.... ...0 = UEA7: Not supported

0... .... = Spare bit(s): 0x0

.1.. .... = UIA1: Supported

..0. .... = UIA2: Not supported

...0 .... = UIA3: Not supported

.... 0... = UIA4: Not supported

.... .0.. = UIA5: Not supported

.... ..0. = UIA6: Not supported

.... ...0 = UIA7: Not supported

(5) UplinkNasTransport

This is the UplinkNASTransport message which is essential in scenarios where the UE needs to send information to the core network that requires secure transport, such as signaling for service request, response to authentication, or any NAS signaling related to mobility management and session management in 5G.

The contents of the message in this example consists of several information elements (IEs):

:id-AMF-UE-NGAP-ID (Item 0): This IE holds an identifier assigned by the Access and Mobility Management Function (AMF) to the UE for NGAP signaling. Here, the value is 102, which uniquely identifies the UE's NGAP context at the AMF.
id-RAN-UE-NGAP-ID (Item 1): Similar to the AMF-UE-NGAP-ID, this identifier is assigned by the Radio Access Network (RAN) to the UE within the NGAP signaling context. The provided value is 1.
id-NAS-PDU (Item 2): This IE contains the NAS protocol data unit that is being transported from the UE to the AMF. The NAS message is security protected, as indicated by the security header type (Integrity protected and ciphered with new 5GS security context). The presence of an authentication code and sequence number suggests that this message is part of an established security context. The content of the NAS-PDU is encrypted, which is why we see Encrypted data rather than plain-text information.
id-UserLocationInformation (Item 3): Provides the location of the UE in terms of NR (New Radio) cell global identifier and tracking area identifier, with specific PLMN identity codes. This information is used by the network to manage the UE's mobility and to deliver services appropriately.

Internet Protocol Version 4, Src: 10.0.0.185, Dst: 10.0.0.162

0100 .... = Version: 4

.... 0101 = Header Length: 20 bytes (5)

Differentiated Services Field: 0x02 (DSCP: CS0, ECN: ECT(0))

0000 00.. = Differentiated Services Codepoint: Default (0)

.... ..10 = Explicit Congestion Notification: ECN-Capable Transport codepoint '10' (2)

Total Length: 132

Identification: 0x000a (10)

Flags: 0x40, Don't fragment

0... .... = Reserved bit: Not set

.1.. .... = Don't fragment: Set

..0. .... = More fragments: Not set

Fragment Offset: 0

Time to Live: 64

Protocol: SCTP (132)

Header Checksum: 0x2490 [validation disabled]

[Header checksum status: Unverified]

Source Address: 10.0.0.185

Destination Address: 10.0.0.162

Stream Control Transmission Protocol, Src Port: 48041 (48041), Dst Port: 38412 (38412)

Source port: 48041

Destination port: 38412

Verification tag: 0x790ad620

[Association index: 65535]

Checksum: 0xb39a1aad [unverified]

[Checksum Status: Unverified]

SACK chunk (Cumulative TSN: 4169966868, a_rwnd: 106496, gaps: 0, duplicate TSNs: 0)

Chunk type: SACK (3)

0... .... = Bit: Stop processing of the packet

.0.. .... = Bit: Do not report

Chunk flags: 0x00

.... ...0 = Nounce sum: 0

Chunk length: 16

Cumulative TSN ACK: 4169966868

[Acknowledges TSN: 4169966868]

[Acknowledges TSN in frame: 886]

[The RTT since DATA was: 0.046143403 seconds]

Advertised receiver window credit (a_rwnd): 106496

Number of gap acknowledgement blocks: 0

Number of duplicated TSNs: 0

DATA chunk(ordered, complete segment, TSN: 3757580130, SID: 1, SSN: 1, PPID: 60,

payload length: 65 bytes)

Chunk type: DATA (0)

0... .... = Bit: Stop processing of the packet

.0.. .... = Bit: Do not report

Chunk flags: 0x03

.... 0... = I-Bit: Possibly delay SACK

.... .0.. = U-Bit: Ordered delivery

.... ..1. = B-Bit: First segment

.... ...1 = E-Bit: Last segment

Chunk length: 81

Transmission sequence number: 3757580130

[This chunk is acked in frame: 894]

[The RTT to SACK was: 0.000370058 seconds]

Stream identifier: 0x0001

Stream sequence number: 1

Payload protocol identifier: NGAP (60)

Chunk padding: 000000

NG Application Protocol

NGAP-PDU: initiatingMessage (0)

initiatingMessage

procedureCode: id-UplinkNASTransport (46)

criticality: ignore (1)

value

UplinkNASTransport

protocolIEs: 4 items

Item 0: id-AMF-UE-NGAP-ID

ProtocolIE-Field

id: id-AMF-UE-NGAP-ID (10)

criticality: reject (0)

value

AMF-UE-NGAP-ID: 102

Item 1: id-RAN-UE-NGAP-ID

ProtocolIE-Field

id: id-RAN-UE-NGAP-ID (85)

criticality: reject (0)

value

RAN-UE-NGAP-ID: 1

Item 2: id-NAS-PDU

ProtocolIE-Field

id: id-NAS-PDU (38)

criticality: reject (0)

value

NAS-PDU: 7e04d3e72791087e005e7700098596500765532619f3

Non-Access-Stratum 5GS (NAS)PDU

Security protected NAS 5GS message

Extended protocol discriminator:

5G mobility management messages (126)

0000 .... = Spare Half Octet: 0

.... 0100 = Security header type:

Integrity protected and ciphered

with new 5GS security context (4)

Message authentication code: 0xd3e72791

Sequence number: 8

Encrypted data

Item 3: id-UserLocationInformation

ProtocolIE-Field

id: id-UserLocationInformation (121)

criticality: ignore (1)

value

UserLocationInformation: userLocationInformationNR (1)

userLocationInformationNR

nR-CGI

pLMNIdentity: 00f110

Mobile Country Code (MCC): Unknown (1)

Mobile Network Code (MNC): Unknown (01)

nRCellIdentity: 0x0001234501

tAI

pLMNIdentity: 00f110

Mobile Country Code (MCC): Unknown (1)

Mobile Network Code (MNC): Unknown (01)

tAC: 100 (0x000064)

(6) InitialContextSetupRequest

The InitialContextSetupRequest is used to establish the necessary user plane and control plane contexts for a UE (User Equipment) at the gNodeB. This message initiates the process of setting up the initial context after a UE has been successfully authenticated and authorized to access the network's services. It is a critical step in the 5G call flow that configures the user and control plane contexts for the UE, setting the stage for all subsequent communications over the 5G network.

The message includes several IEs (Information Elements) that provide the gNodeB with information needed to configure resources for the UE:

id-AMF-UE-NGAP-ID (Item 0): A unique identifier allocated by the AMF for the UE.
id-RAN-UE-NGAP-ID (Item 1): A unique identifier allocated by the gNodeB for the UE.
id-GUAMI (Item 2): The Globally Unique AMF Identifier, which specifies the AMF that serves the UE, including the PLMN Identity, AMF Region ID, AMF Set ID, and AMF Pointer.
id-AllowedNSSAI (Item 3): The list of allowed S-NSSAIs (Single Network Slice Selection Assistance Information) for the UE, which identifies the slices that the UE is allowed to access.
id-UESecurityCapabilities (Item 4): The security capabilities of the UE, detailing the supported encryption and integrity protection algorithms for both NR (New Radio) and E-UTRA (Evolved UTRA).
id-SecurityKey (Item 5): The security key to be used by the gNodeB for securing the signaling and user plane data.
id-NAS-PDU (Item 6): The NAS (Non-Access Stratum) protocol data unit containing encrypted data. This NAS message is typically used to carry out the signaling needed for mobility management, session management, and other NAS functions.
id-RedirectionVoiceFallback (Item 7): Indicates whether voice fallback is possible for the UE, in case the UE needs to be redirected to a legacy voice service when VoNR (Voice over New Radio) is not available.

Internet Protocol Version 4, Src: 10.0.0.162, Dst: 10.0.0.185

0100 .... = Version: 4

.... 0101 = Header Length: 20 bytes (5)

Differentiated Services Field: 0x02 (DSCP: CS0, ECN: ECT(0))

0000 00.. = Differentiated Services Codepoint: Default (0)

.... ..10 = Explicit Congestion Notification: ECN-Capable Transport codepoint '10' (2)

Total Length: 216

Identification: 0xadd9 (44505)

Flags: 0x40, Don't fragment

0... .... = Reserved bit: Not set

.1.. .... = Don't fragment: Set

..0. .... = More fragments: Not set

Fragment Offset: 0

Time to Live: 64

Protocol: SCTP (132)

Header Checksum: 0x766c [validation disabled]

[Header checksum status: Unverified]

Source Address: 10.0.0.162

Destination Address: 10.0.0.185

Stream Control Transmission Protocol, Src Port: 38412 (38412), Dst Port: 48041 (48041)

Source port: 38412

Destination port: 48041

Verification tag: 0x8d10a6cf

[Association index: 65535]

Checksum: 0x564117e2 [unverified]

[Checksum Status: Unverified]

SACK chunk (Cumulative TSN: 3757580130, a_rwnd: 106496, gaps: 0, duplicate TSNs: 0)

Chunk type: SACK (3)

0... .... = Bit: Stop processing of the packet

.0.. .... = Bit: Do not report

Chunk flags: 0x00

.... ...0 = Nounce sum: 0

Chunk length: 16

Cumulative TSN ACK: 3757580130

[Acknowledges TSN: 3757580130]

[Acknowledges TSN in frame: 893]

[The RTT since DATA was: 0.000370058 seconds]

Advertised receiver window credit (a_rwnd): 106496

Number of gap acknowledgement blocks: 0

Number of duplicated TSNs: 0

DATA chunk(ordered, complete segment, TSN: 4169966869, SID: 1, SSN: 1, PPID: 60,

payload length: 152 bytes)

Chunk type: DATA (0)

0... .... = Bit: Stop processing of the packet

.0.. .... = Bit: Do not report

Chunk flags: 0x03

.... 0... = I-Bit: Possibly delay SACK

.... .0.. = U-Bit: Ordered delivery

.... ..1. = B-Bit: First segment

.... ...1 = E-Bit: Last segment

Chunk length: 168

Transmission sequence number: 4169966869

[This chunk is acked in frame: 901]

[The RTT to SACK was: 0.131696577 seconds]

Stream identifier: 0x0001

Stream sequence number: 1

Payload protocol identifier: NGAP (60)

NG Application Protocol

NGAP-PDU: initiatingMessage (0)

initiatingMessage

procedureCode: id-InitialContextSetup (14)

criticality: reject (0)

value

InitialContextSetupRequest

protocolIEs: 8 items

Item 0: id-AMF-UE-NGAP-ID

ProtocolIE-Field

id: id-AMF-UE-NGAP-ID (10)

criticality: reject (0)

value

AMF-UE-NGAP-ID: 102

Item 1: id-RAN-UE-NGAP-ID

ProtocolIE-Field

id: id-RAN-UE-NGAP-ID (85)

criticality: reject (0)

value

RAN-UE-NGAP-ID: 1

Item 2: id-GUAMI

ProtocolIE-Field

id: id-GUAMI (28)

criticality: reject (0)

value

GUAMI

pLMNIdentity: 00f110

Mobile Country Code (MCC): Unknown (1)

Mobile Network Code (MNC): Unknown (01)

aMFRegionID: 80 [bit length 8, 1000 0000 decimal value 128]

aMFSetID: 0100 [bit length 10, 6 LSB pad bits,

0000 0001 00.. .... decimal value 4]

aMFPointer: 04 [bit length 6, 2 LSB pad bits,

0000 01.. decimal value 1]

Item 3: id-AllowedNSSAI

ProtocolIE-Field

id: id-AllowedNSSAI (0)

criticality: reject (0)

value

AllowedNSSAI: 1 item

Item 0

AllowedNSSAI-Item

s-NSSAI

sST: 01

Item 4: id-UESecurityCapabilities

ProtocolIE-Field

id: id-UESecurityCapabilities (119)

criticality: reject (0)

value

UESecurityCapabilities

nRencryptionAlgorithms: e000 [bit length 16,

1110 0000 0000 0000 decimal value 57344]

1... .... .... .... = 128-NEA1: Supported

.1.. .... .... .... = 128-NEA2: Supported

..1. .... .... .... = 128-NEA3: Supported

...0 0000 0000 0000 = Reserved: 0x0000

nRintegrityProtectionAlgorithms: e000 [bit length 16,

1110 0000 0000 0000 decimal value 57344]

1... .... .... .... = 128-NIA1: Supported

.1.. .... .... .... = 128-NIA2: Supported

..1. .... .... .... = 128-NIA3: Supported

...0 0000 0000 0000 = Reserved: 0x0000

eUTRAencryptionAlgorithms: e000 [bit length 16,

1110 0000 0000 0000 decimal value 57344]

1... .... .... .... = 128-EEA1: Supported

.1.. .... .... .... = 128-EEA2: Supported

..1. .... .... .... = 128-EEA3: Supported

...0 0000 0000 0000 = Reserved: 0x0000

eUTRAintegrityProtectionAlgorithms: e000 [bit length 16,

1110 0000 0000 0000 decimal value 57344]

1... .... .... .... = 128-EIA1: Supported

.1.. .... .... .... = 128-EIA2: Supported

..1. .... .... .... = 128-EIA3: Supported

...0 0000 0000 0000 = Reserved: 0x0000

Item 5: id-SecurityKey

ProtocolIE-Field

id: id-SecurityKey (94)

criticality: reject (0)

value

SecurityKey: 0cf3d559d8db4b4cb2193a8bbda7... [bit length 256]

Item 6: id-NAS-PDU

ProtocolIE-Field

id: id-NAS-PDU (38)

criticality: ignore (1)

value

NAS-PDU: 7e02989f23dc077e0042010977000bf200f110800101

Non-Access-Stratum 5GS (NAS)PDU

Security protected NAS 5GS message

Extended protocol discriminator:

5G mobility management messages (126)

0000 .... = Spare Half Octet: 0

.... 0010 = Security header type:

Integrity protected and ciphered (2)

Message authentication code: 0x989f23dc

Sequence number: 7

Encrypted data

Item 7: id-RedirectionVoiceFallback

ProtocolIE-Field

id: id-RedirectionVoiceFallback (146)

criticality: ignore (1)

value

RedirectionVoiceFallback: possible (0)

(7) UERadioCapabilityInformation

This carries Rrc UE capability Information message. This part is not printed in this note since this is more like Rrc Information.

(8) InitialContextSetupRequest

The InitialContextSetupResponse is sent by the gNodeB to the AMF as part of the UE's initial context setup process. This message indicates a successful outcome of the initial context setup procedure initiated by the InitialContextSetupRequest. It indicates that the gNodeB has successfully set up the context for the UE as requested by the AMF. This setup includes the allocation of necessary resources and configurations to facilitate communication with the UE, such as radio bearers and security configurations. The successful outcome allows the UE to proceed with further communication and data transfer over the 5G network.

This response contains two main information elements (IEs):

id-AMF-UE-NGAP-ID (Item 0): This is the unique identifier that the AMF has assigned to the UE. It is used by the AMF to identify the UE within the NGAP messages. In this case, the value is 102.
id-RAN-UE-NGAP-ID (Item 1): This is the unique identifier that the gNodeB has assigned to the UE. It is used by the gNodeB to keep track of the UE's NGAP context. Here, the identifier is 1.

Internet Protocol Version 4, Src: 10.0.0.185, Dst: 10.0.0.162

0100 .... = Version: 4

.... 0101 = Header Length: 20 bytes (5)

Differentiated Services Field: 0x02 (DSCP: CS0, ECN: ECT(0))

0000 00.. = Differentiated Services Codepoint: Default (0)

.... ..10 = Explicit Congestion Notification: ECN-Capable Transport codepoint '10' (2)

Total Length: 68

Identification: 0x000d (13)

Flags: 0x40, Don't fragment

0... .... = Reserved bit: Not set

.1.. .... = Don't fragment: Set

..0. .... = More fragments: Not set

Fragment Offset: 0

Time to Live: 64

Protocol: SCTP (132)

Header Checksum: 0x24cd [validation disabled]

[Header checksum status: Unverified]

Source Address: 10.0.0.185

Destination Address: 10.0.0.162

Stream Control Transmission Protocol, Src Port: 48041 (48041), Dst Port: 38412 (38412)

Source port: 48041

Destination port: 38412

Verification tag: 0x790ad620

[Association index: 65535]

Checksum: 0x2c975cf3 [unverified]

[Checksum Status: Unverified]

DATA chunk(ordered, complete segment, TSN: 3757580133, SID: 1, SSN: 3, PPID: 60,

payload length: 19 bytes)

Chunk type: DATA (0)

0... .... = Bit: Stop processing of the packet

.0.. .... = Bit: Do not report

Chunk flags: 0x03

.... 0... = I-Bit: Possibly delay SACK

.... .0.. = U-Bit: Ordered delivery

.... ..1. = B-Bit: First segment

.... ...1 = E-Bit: Last segment

Chunk length: 35

Transmission sequence number: 3757580133

[This chunk is acked in frame: 907]

[The RTT to SACK was: 0.000376547 seconds]

Stream identifier: 0x0001

Stream sequence number: 3

Payload protocol identifier: NGAP (60)

Chunk padding: 00

NG Application Protocol

NGAP-PDU: successfulOutcome (1)

successfulOutcome

procedureCode: id-InitialContextSetup (14)

criticality: reject (0)

value

InitialContextSetupResponse

protocolIEs: 2 items

Item 0: id-AMF-UE-NGAP-ID

ProtocolIE-Field

id: id-AMF-UE-NGAP-ID (10)

criticality: ignore (1)

value

AMF-UE-NGAP-ID: 102

Item 1: id-RAN-UE-NGAP-ID

ProtocolIE-Field

id: id-RAN-UE-NGAP-ID (85)

criticality: ignore (1)

value

RAN-UE-NGAP-ID: 1

(9) UplinkNASTransport

The UplinkNASTransport message is sent from the gNodeB to the AMF (Access and Mobility Management Function) and is responsible for transporting NAS messages from the UE to the core network. It is crucial for the delivery of NAS messages that are typically related to mobility management, session management, or authentication to the AMF from the UE. It allows the core network to receive information from the UE, process it, and take necessary actions based on the content of the NAS message.

The message consists of the following information elements (IEs):

id-AMF-UE-NGAP-ID (Item 0):This IE contains a unique identifier for the UE provided by the AMF, which, in this instance, is 102. This ID is used for NGAP session management between the AMF and the gNodeB.
id-RAN-UE-NGAP-ID (Item 1): This IE holds a unique identifier for the UE provided by the RAN (Radio Access Network), which is 1. This ID is used for NGAP session management within the RAN.
id-NAS-PDU (Item 2): This IE contains the NAS message that the UE wants to transmit to the core network. It is a security-protected message, meaning it has been both integrity-protected and ciphered. This includes an extended protocol discriminator, security header type, message authentication code, sequence number, and the actual encrypted NAS message data.
id-UserLocationInformation (Item 3): This IE provides the location information of the UE, in terms of the cell identity (nR-CGI) and the tracking area identity (tAI) associated with the cell where the UE is located. Both are provided along with the PLMN Identity, which comprises the Mobile Country Code (MCC) and Mobile Network Code (MNC).

Internet Protocol Version 4, Src: 10.0.0.185, Dst: 10.0.0.162

0100 .... = Version: 4

.... 0101 = Header Length: 20 bytes (5)

Differentiated Services Field: 0x02 (DSCP: CS0, ECN: ECT(0))

0000 00.. = Differentiated Services Codepoint: Default (0)

.... ..10 = Explicit Congestion Notification: ECN-Capable Transport codepoint '10' (2)

Total Length: 104

Identification: 0x000e (14)

Flags: 0x40, Don't fragment

0... .... = Reserved bit: Not set

.1.. .... = Don't fragment: Set

..0. .... = More fragments: Not set

Fragment Offset: 0

Time to Live: 64

Protocol: SCTP (132)

Header Checksum: 0x24a8 [validation disabled]

[Header checksum status: Unverified]

Source Address: 10.0.0.185

Destination Address: 10.0.0.162

Stream Control Transmission Protocol, Src Port: 48041 (48041), Dst Port: 38412 (38412)

Source port: 48041

Destination port: 38412

Verification tag: 0x790ad620

[Association index: 65535]

Checksum: 0x4643a66d [unverified]

[Checksum Status: Unverified]

DATA chunk(ordered, complete segment, TSN: 3757580134, SID: 1, SSN: 4, PPID: 60,

payload length: 53 bytes)

Chunk type: DATA (0)

0... .... = Bit: Stop processing of the packet

.0.. .... = Bit: Do not report

Chunk flags: 0x03

.... 0... = I-Bit: Possibly delay SACK

.... .0.. = U-Bit: Ordered delivery

.... ..1. = B-Bit: First segment

.... ...1 = E-Bit: Last segment

Chunk length: 69

Transmission sequence number: 3757580134

[This chunk is acked in frame: 907]

[The RTT to SACK was: 0.000018275 seconds]

Stream identifier: 0x0001

Stream sequence number: 4

Payload protocol identifier: NGAP (60)

Chunk padding: 000000

NG Application Protocol

NGAP-PDU: initiatingMessage (0)

initiatingMessage

procedureCode: id-UplinkNASTransport (46)

criticality: ignore (1)

value

UplinkNASTransport

protocolIEs: 4 items

Item 0: id-AMF-UE-NGAP-ID

ProtocolIE-Field

id: id-AMF-UE-NGAP-ID (10)

criticality: reject (0)

value

AMF-UE-NGAP-ID: 102

Item 1: id-RAN-UE-NGAP-ID

ProtocolIE-Field

id: id-RAN-UE-NGAP-ID (85)

criticality: reject (0)

value

RAN-UE-NGAP-ID: 1

Item 2: id-NAS-PDU

ProtocolIE-Field

id: id-NAS-PDU (38)

criticality: reject (0)

value

NAS-PDU: 7e021bc4e845097e0043

Non-Access-Stratum 5GS (NAS)PDU

Security protected NAS 5GS message

Extended protocol discriminator:

5G mobility management messages (126)

0000 .... = Spare Half Octet: 0

.... 0010 = Security header type:

Integrity protected and ciphered (2)

Message authentication code: 0x1bc4e845

Sequence number: 9

Encrypted data

Item 3: id-UserLocationInformation

ProtocolIE-Field

id: id-UserLocationInformation (121)

criticality: ignore (1)

value

UserLocationInformation: userLocationInformationNR (1)

userLocationInformationNR

nR-CGI

pLMNIdentity: 00f110

Mobile Country Code (MCC): Unknown (1)

Mobile Network Code (MNC): Unknown (01)

nRCellIdentity: 0x0001234501

tAI

pLMNIdentity: 00f110

Mobile Country Code (MCC): Unknown (1)

Mobile Network Code (MNC): Unknown (01)

tAC: 100 (0x000064)

(10) DownlinkNASTransport

The DownlinkNASTransport is used in 5G networks to communicate from the core network to the gNodeB, specifically for the purpose of delivering NAS messages to the UE. It is used for a variety of purposes, including delivering commands from the core network to the UE, such as service accept or reject messages, authentication requests, or security mode commands. This secure transport of NAS messages ensures that commands and responses between the UE and the core network maintain their confidentiality and integrity as they pass through the radio interface.

This message contains three primary information elements (IEs):

id-AMF-UE-NGAP-ID (Item 0): This is the identifier for the UE as known by the AMF (Access and Mobility Management Function), which is 102 in this particular message. It's used to reference the UE within the AMF.
id-RAN-UE-NGAP-ID (Item 1): This is the identifier for the UE as known by the RAN (Radio Access Network), which is 1 in this message. It's used for signaling and managing the context between the UE and the gNodeB.
id-NAS-PDU (Item 2): This carries the actual NAS message that needs to be delivered to the UE. The NAS message in this IE is security-protected, which means it has been both integrity-protected and ciphered, as indicated by the security header type Integrity protected and ciphered. It includes a message authentication code (MAC) and a sequence number, which are part of the security mechanism to ensure the integrity and authenticity of the message. The content of the NAS-PDU is encrypted, so the details of the message are not visible in this snippet.

Internet Protocol Version 4, Src: 10.0.0.162, Dst: 10.0.0.185

0100 .... = Version: 4

.... 0101 = Header Length: 20 bytes (5)

Differentiated Services Field: 0x02 (DSCP: CS0, ECN: ECT(0))

0000 00.. = Differentiated Services Codepoint: Default (0)

.... ..10 = Explicit Congestion Notification: ECN-Capable Transport codepoint '10' (2)

Total Length: 124

Identification: 0xaddc (44508)

Flags: 0x40, Don't fragment

0... .... = Reserved bit: Not set

.1.. .... = Don't fragment: Set

..0. .... = More fragments: Not set

Fragment Offset: 0

Time to Live: 64

Protocol: SCTP (132)

Header Checksum: 0x76c5 [validation disabled]

[Header checksum status: Unverified]

Source Address: 10.0.0.162

Destination Address: 10.0.0.185

Stream Control Transmission Protocol, Src Port: 38412 (38412), Dst Port: 48041 (48041)

Source port: 38412

Destination port: 48041

Verification tag: 0x8d10a6cf

[Association index: 65535]

Checksum: 0xd913f52a [unverified]

[Checksum Status: Unverified]

DATA chunk(ordered, complete segment, TSN: 4169966870, SID: 1, SSN: 2, PPID: 60,

payload length: 76 bytes)

Chunk type: DATA (0)

0... .... = Bit: Stop processing of the packet

.0.. .... = Bit: Do not report

Chunk flags: 0x03

.... 0... = I-Bit: Possibly delay SACK

.... .0.. = U-Bit: Ordered delivery

.... ..1. = B-Bit: First segment

.... ...1 = E-Bit: Last segment

Chunk length: 92

Transmission sequence number: 4169966870

[This chunk is acked in frame: 909]

[The RTT to SACK was: 0.299073623 seconds]

Stream identifier: 0x0001

Stream sequence number: 2

Payload protocol identifier: NGAP (60)

NG Application Protocol

NGAP-PDU: initiatingMessage (0)

initiatingMessage

procedureCode: id-DownlinkNASTransport (4)

criticality: ignore (1)

value

DownlinkNASTransport

protocolIEs: 3 items

Item 0: id-AMF-UE-NGAP-ID

ProtocolIE-Field

id: id-AMF-UE-NGAP-ID (10)

criticality: reject (0)

value

AMF-UE-NGAP-ID: 102

Item 1: id-RAN-UE-NGAP-ID

ProtocolIE-Field

id: id-RAN-UE-NGAP-ID (85)

criticality: reject (0)

value

RAN-UE-NGAP-ID: 1

Item 2: id-NAS-PDU

ProtocolIE-Field

id: id-NAS-PDU (38)

criticality: reject (0)

value

NAS-PDU: 7e02708c9be0087e0054431081c176589e9ebfcd

Non-Access-Stratum 5GS (NAS)PDU

Security protected NAS 5GS message

Extended protocol discriminator:

5G mobility management messages (126)

0000 .... = Spare Half Octet: 0

.... 0010 = Security header type:

Integrity protected and ciphered (2)

Message authentication code: 0x708c9be0

Sequence number: 8

Encrypted data

(11) UplinkNASTransport

The UplinkNASTransport message is used within the 5G network for conveying NAS messages from the UE to the core network, specifically the AMF, through the gNodeB. It plays a vital role in the communication between the UE and the core network, especially for processes that require secure transport, such as authentication response, service request, or any mobility management message from the UE.

This message consists of the following key information elements (IEs):

id-AMF-UE-NGAP-ID (Item 0): A unique identifier allocated by the AMF for the UE, used to identify the NGAP context for the UE at the AMF. In this message, the ID is 102.
id-RAN-UE-NGAP-ID (Item 1): A unique identifier allocated by the RAN to the UE within its NGAP context. The RAN uses this ID to manage and maintain context for the UE. The provided identifier is 1.
id-NAS-PDU (Item 2): Contains the NAS message payload that needs to be transported to the AMF. The NAS PDU includes a security header that indicates the message is both integrity protected and ciphered, a message authentication code for integrity verification, and the encrypted content of the NAS message. The sequence number (10 in this case) is used to maintain the order of NAS messages and protect against replay attacks.
id-UserLocationInformation (Item 3): Provides the geographical location of the UE, including the NR (New Radio) cell global identifier (nR-CGI) and the tracking area identity (tAI), which are associated with the cell where the UE is currently located. The PLMN Identity is part of this information, typically comprising the Mobile Country Code (MCC) and Mobile Network Code (MNC), although they are marked as unknown in this message.

Internet Protocol Version 4, Src: 10.0.0.185, Dst: 10.0.0.162

0100 .... = Version: 4

.... 0101 = Header Length: 20 bytes (5)

Differentiated Services Field: 0x02 (DSCP: CS0, ECN: ECT(0))

0000 00.. = Differentiated Services Codepoint: Default (0)

.... ..10 = Explicit Congestion Notification: ECN-Capable Transport codepoint '10' (2)

Total Length: 228

Identification: 0x0010 (16)

Flags: 0x40, Don't fragment

0... .... = Reserved bit: Not set

.1.. .... = Don't fragment: Set

..0. .... = More fragments: Not set

Fragment Offset: 0

Time to Live: 64

Protocol: SCTP (132)

Header Checksum: 0x242a [validation disabled]

[Header checksum status: Unverified]

Source Address: 10.0.0.185

Destination Address: 10.0.0.162

Stream Control Transmission Protocol, Src Port: 48041 (48041), Dst Port: 38412 (38412)

Source port: 48041

Destination port: 38412

Verification tag: 0x790ad620

[Association index: 65535]

Checksum: 0x39273ca9 [unverified]

[Checksum Status: Unverified]

DATA chunk(ordered, complete segment, TSN: 3757580135, SID: 1, SSN: 5, PPID: 60,

payload length: 180 bytes)

Chunk type: DATA (0)

0... .... = Bit: Stop processing of the packet

.0.. .... = Bit: Do not report

Chunk flags: 0x03

.... 0... = I-Bit: Possibly delay SACK

.... .0.. = U-Bit: Ordered delivery

.... ..1. = B-Bit: First segment

.... ...1 = E-Bit: Last segment

Chunk length: 196

Transmission sequence number: 3757580135

[This chunk is acked in frame: 911]

[The RTT to SACK was: 0.000140996 seconds]

Stream identifier: 0x0001

Stream sequence number: 5

Payload protocol identifier: NGAP (60)

NG Application Protocol

NGAP-PDU: initiatingMessage (0)

initiatingMessage

procedureCode: id-UplinkNASTransport (46)

criticality: ignore (1)

value

UplinkNASTransport

protocolIEs: 4 items

Item 0: id-AMF-UE-NGAP-ID

ProtocolIE-Field

id: id-AMF-UE-NGAP-ID (10)

criticality: reject (0)

value

AMF-UE-NGAP-ID: 102

Item 1: id-RAN-UE-NGAP-ID

ProtocolIE-Field

id: id-RAN-UE-NGAP-ID (85)

criticality: reject (0)

value

RAN-UE-NGAP-ID: 1

Item 2: id-NAS-PDU

ProtocolIE-Field

id: id-NAS-PDU (38)

criticality: reject (0)

value

NAS-PDU: 7e02c3faa3fa0a7e006701006b2e0114c1000093280100

Non-Access-Stratum 5GS (NAS)PDU

Security protected NAS 5GS message

Extended protocol discriminator:

5G mobility management messages (126)

0000 .... = Spare Half Octet: 0

.... 0010 = Security header type:

Integrity protected and ciphered (2)

Message authentication code: 0xc3faa3fa

Sequence number: 10

Encrypted data

Item 3: id-UserLocationInformation

ProtocolIE-Field

id: id-UserLocationInformation (121)

criticality: ignore (1)

value

UserLocationInformation: userLocationInformationNR (1)

userLocationInformationNR

nR-CGI

pLMNIdentity: 00f110

Mobile Country Code (MCC): Unknown (1)

Mobile Network Code (MNC): Unknown (01)

nRCellIdentity: 0x0001234501

tAI

pLMNIdentity: 00f110

Mobile Country Code (MCC): Unknown (1)

Mobile Network Code (MNC): Unknown (01)

tAC: 100 (0x000064)

UPLINK NAS TRANSPORT

The Uplink NAS Transport procedure is used when the NG-RAN node has received from the radio interface a NAS message to be forwarded to the AMF to which a UE-associated logical NG-connection for the UE exists. Most of NAS message sent by UE is conveyed to core network via Uplink Nas Transport.

The NG-RAN node initiates the procedure by sending an UPLINK NAS TRANSPORT message to the AMF.
The NAS-PDU IE contains a UE AMF message that is transferred without interpretation in the NG-RAN node.

< 38.413-Figure 8.6.3.2-1: Uplink NAS transport >

< 38.413 - 9.2.5.3 >

IE/Group Name	Presence	IE type and reference	Semantics description	Criticality	Assigned Criticality
Message Type	M	9.3.1.1		YES	ignore
AMF UE NGAP ID	M	9.3.3.1	reject	YES	reject
RAN UE NGAP ID	M	9.3.3.2		YES	reject
NAS-PDU	M	9.3.3.4		YES	reject
User Location Information	M	9.3.1.16		YES	ignore
W-AGF Identity Information	O	OCTET STRING	Containing the WAgfInfo IE specified in TS 29.510	YES	reject
TNGF Identity Information	O	OCTET STRING	Containing the TngfInfo IE specified in TS 29.510	YES	reject
TWIF Identity Information	O	OCTET STRING	Containing the TwifInfo IE specified in TS 29.510	YES	reject

< 29.510 - Table 6.1.6.2.51-1: Definition of type WAgfInfo >

< 29.510 - Table 6.1.6.2.52-1: Definition of type TngfInfo >

< 29.510 - Table 6.1.6.2.61-1: Definition of type TwifInfo >

AMF UE NGAP ID (38.401-6.2.1): An AMF UE NGAP ID shall be allocated so as to uniquely identify the UE over the NG interface within the AMF. When a NG-RAN node receives an AMF UE NGAP ID it shall store it for the duration of the UEassociated logical NG-connection for this UE. Once known to a NG-RAN node this ID is included in all UE associated NGAP signalling.

RAN UE NGAP ID (38.401-6.2.1): A RAN UE NGAP ID shall be allocated so as to uniquely identify the UE over the NG interface within an gNB. When an AMF receives an RAN UE NGAP ID it shall store it for the duration of the UE-associated logical NGconnection for this UE. Once known to an AMF this is included in all UE associated NGAP signalling. The RAN UE NGAP ID shall be unique within the logical NG-RAN node.

Example 1 >

initiatingMessage: {

procedureCode id-UplinkNASTransport,

criticality ignore,

value {

protocolIEs {

{

id id-AMF-UE-NGAP-ID,

criticality reject,

value 100

{

id id-RAN-UE-NGAP-ID,

criticality reject,

value 1

{

id id-NAS-PDU,

criticality reject,

value '7E0118....'H // NAS message is contained here, decoded by AMF to NAS message

{

id id-UserLocationInformation,

criticality ignore,

value userLocationInformationNR: {

nR-CGI {

pLMNIdentity '00F110'H,

nRCellIdentity '001234501'H

tAI {

pLMNIdentity '00F110'H,

tAC '000064'H

}

NOTE : common NAS messages carried by Uplink NAS transport

Identity request
Authentication request
Authentication response
Security mode complete
Registration complete
PDU session establishment request

DOWNLINK NAS TRANSPORT

The Downlink NAS Transport procedure is used when the AMF only needs to send a NAS message transparently via the NG-RAN node to the UE, and a UE-associated logical NG-connection exists for the UE or the AMF has received the RAN UE NGAP ID IE in an INITIAL UE MESSAGE message or if the NG-RAN node has already initiated a UEassociated logical NG-connection by sending an INITIAL UE MESSAGE message via another NG interface instance.

< 38.413-Figure 8.6.2.2-1: Downlink NAS transport >

< 38.413 - 9.2.5.2 >

IE/Group Name	Presence	IE type and reference	Semantics description	Criticality	Assigned action
Message Type	M	9.3.1.1		YES	ignore
AMF UE NGAP ID	M	9.3.1.1		YES	reject
RAN UE NGAP ID	M	9.3.3.2		YES	reject
Old AMF	O	AMF name 9.3.3.21		YES	reject
RAN Paging Priority	O	9.3.3.15		YES	ignore
NAS-PDU	M	9.3.3.4		YES	reject
Mobility Restriction List	O	9.3.1.85		YES	ignore
Index to RAI/Frequency Selection Priority	O	9.3.1.61		YES	ignore
UE Aggregate Maximum Bit Rate	O	9.3.1.58		YES	ignore
Allowed NSSAI	O	9.3.1.31	Indicates the S-NSSAIs permitted by the network.	YES	reject
SRVCC Operation Possible	O	9.3.1.128		YES	ignore
Enhanced Coverage Restriction	O	9.3.1.140		YES	ignore
Extended Connected Time	O	9.3.3.31		YES	ignore
UE Differentiation Information	O	9.3.1.144		YES	ignore
CE-mode-B Restricted	O	9.3.1.155		YES	ignore
UE Radio Capability	O	9.3.1.74
UE Capability Info Request	O	9.3.1.192		YES	ignore
End Indication	O	9.3.3.32		YES	ignore
UE Radio Capability ID	O	9.3.1.142		YES	reject
Target NSSAI Information	O	9.3.1.229		YES	ignore
Masked IMEISV	O	9.3.1.54		YES	ignore

Example 1 >

initiatingMessage: {

procedureCode id-DownlinkNASTransport,

criticality ignore,

value {

protocolIEs {

{

id id-AMF-UE-NGAP-ID,

criticality reject,

value 100

{

id id-RAN-UE-NGAP-ID,

criticality reject,

value 1

{

id id-NAS-PDU,

criticality reject,

value '7E03....'H // NAS message is contained here, decoded by gNB to NAS message

}

NOTE : common NAS messages carried by Downlink NAS transport

Identity response
Authentication response
Security mode command
Configuration update command
PDU session establishment accept

PDU Session Resource Setup

The purpose of the PDU Session Resource Setup is as follows :

assign resources on Uu and NG-U for one or several PDU sessions and the corresponding QoS flows
setup corresponding DRBs for a given UE

Overall signaling procecedure is as follows and the details are described in 38.413 - 8.2.1.

< 38.413 - Figure 8.2.1.2-1: PDU session resource setup: successful operation >

This process is the one that get a huge list of parameters involved. The details are described in 38.413-8.2.1, but it doesn't make clear sense to me yet. I would need more study and log analysis for deeper understanding. The list of parameters explained in this specification is as follows to give you some generic idea.

PDU SESSION RESOURCE SETUP REQUEST

PDU Session Resource Setup Request List

DUSessionNAS-PDU
PDU Session ID

RAN Paging Priority
PDU Session Resource Setup Request Transfer IE

UL NG-U UP TNL Information
Additional UL NG-U UP TNL Information
Common Network Instance
Network Instance
UP Transport Layer Information List
Redundant UL NG-U UP TNL Information
Redundant QoS Flow per TNL Information
Additional Redundant DL QoS Flow per TNL Information
TSC Traffic Characteristics
PDU Session Type
Security Indication

Integrity Protection Indication
Confidentiality Protection Indication
Maximum Integrity Protected Data Rate Downlink
Maximum Integrity Protected Data Rate Uplink

PDU Session Aggregate Maximum Bit Rate
QoS Flow Level QoS Parameters

Additional QoS Flow Information
QoS Monitoring Request
Flow Level QoS Parameters

GBR QoS Flow Information

Alternative QoS Parameters Set List

Redundant QoS Flow Indicator
Redundant PDU Session Information
PDU Session Expected UE Activity Behaviour

PDU SESSION RESOURCE SETUP RESPONSE

PDU Session Resource Setup Response Transfer

Integrity Protection Result
Confidentiality Protection Result IE
Current QoS Parameters Set Index
Global RAN Node ID of Secondary NG-RAN Node
QoS Flow per TNL Information
QoS Flow Failed to Setup List
PDU Session Resource Setup Unsuccessful Transfer

(12) PDUSessionResourceSetupRequest

The PDUSessionResourceSetupRequest is a message used within the 5G NGAP to establish PDU sessions, which are the connections that carry the user data between the UE and the network. This request is sent from the AMF to the gNodeB. This message is critical for setting up the PDU session, which includes configuring the transport layer for user plane data and establishing the QoS flows necessary for the UE to send and receive data within the specified service quality constraints. The PDUSessionResourceSetupRequest is a step in the process of connecting the UE to the data network, allowing it to access internet services and other data-centric applications.

Here is the breakdown of the PDUSessionResourceSetupRequest message:

id-AMF-UE-NGAP-ID (Item 0): The unique identifier assigned to the UE by the AMF. In this instance, it is 102.
id-RAN-UE-NGAP-ID (Item 1): The unique identifier assigned to the UE by the RAN. The RAN uses this ID to manage the UE's context, and here it is 1.
id-PDUSessionResourceSetupListSUReq (Item 2): A list that details the PDU sessions to be set up. It includes:

pDUSessionID: The identifier for the PDU session.
pDUSessionNAS-PDU: The NAS message for the PDU session, which is security-protected (integrity protected and ciphered).
s-NSSAI : Specifies the slice of the network that the PDU session will use.
pDUSessionResourceSetupRequestTransfer: Encapsulates several IEs related to the PDU session as follows

PDUSessionAggregateMaximumBitRate: The maximum bit rate for downlink and uplink.
UL-NGU-UP-TNLInformation: Specifies the transport layer information for the uplink, including the IP address and GTP-TEID (GPRS Tunneling Protocol - Tunnel Endpoint Identifier).
PDUSessionType: Indicates the type of PDU session (e.g., IPv4).
QosFlowSetupRequestList: Contains the QoS flows to be established for the session, specifying QoS characteristics like the 5QI and ARP (Allocation and Retention Priority) levels.

id-UEAggregateMaximumBitRate (Item 3): Specifies the maximum bit rates for downlink and uplink for the UE as a whole.

Internet Protocol Version 4, Src: 10.0.0.162, Dst: 10.0.0.185

0100 .... = Version: 4

.... 0101 = Header Length: 20 bytes (5)

Differentiated Services Field: 0x02 (DSCP: CS0, ECN: ECT(0))

0000 00.. = Differentiated Services Codepoint: Default (0)

.... ..10 = Explicit Congestion Notification: ECN-Capable Transport codepoint '10' (2)

Total Length: 292

Identification: 0xaddd (44509)

Flags: 0x40, Don't fragment

0... .... = Reserved bit: Not set

.1.. .... = Don't fragment: Set

..0. .... = More fragments: Not set

Fragment Offset: 0

Time to Live: 64

Protocol: SCTP (132)

Header Checksum: 0x761c [validation disabled]

[Header checksum status: Unverified]

Source Address: 10.0.0.162

Destination Address: 10.0.0.185

Stream Control Transmission Protocol, Src Port: 38412 (38412), Dst Port: 48041 (48041)

Source port: 38412

Destination port: 48041

Verification tag: 0x8d10a6cf

[Association index: 65535]

Checksum: 0xf21498ba [unverified]

[Checksum Status: Unverified]

SACK chunk (Cumulative TSN: 3757580135, a_rwnd: 106496, gaps: 0, duplicate TSNs: 0)

Chunk type: SACK (3)

0... .... = Bit: Stop processing of the packet

.0.. .... = Bit: Do not report

Chunk flags: 0x00

.... ...0 = Nounce sum: 0

Chunk length: 16

Cumulative TSN ACK: 3757580135

[Acknowledges TSN: 3757580135]

[Acknowledges TSN in frame: 910]

[The RTT since DATA was: 0.000140996 seconds]

Advertised receiver window credit (a_rwnd): 106496

Number of gap acknowledgement blocks: 0

Number of duplicated TSNs: 0

DATA chunk(ordered, complete segment, TSN: 4169966871, SID: 1, SSN: 3, PPID: 60,

payload length: 228 bytes)

Chunk type: DATA (0)

0... .... = Bit: Stop processing of the packet

.0.. .... = Bit: Do not report

Chunk flags: 0x03

.... 0... = I-Bit: Possibly delay SACK

.... .0.. = U-Bit: Ordered delivery

.... ..1. = B-Bit: First segment

.... ...1 = E-Bit: Last segment

Chunk length: 244

Transmission sequence number: 4169966871

[This chunk is acked in frame: 914]

[The RTT to SACK was: 0.035658957 seconds]

Stream identifier: 0x0001

Stream sequence number: 3

Payload protocol identifier: NGAP (60)

NG Application Protocol

NGAP-PDU: initiatingMessage (0)

initiatingMessage

procedureCode: id-PDUSessionResourceSetup (29)

criticality: reject (0)

value

PDUSessionResourceSetupRequest

protocolIEs: 4 items

Item 0: id-AMF-UE-NGAP-ID

ProtocolIE-Field

id: id-AMF-UE-NGAP-ID (10)

criticality: reject (0)

value

AMF-UE-NGAP-ID: 102

Item 1: id-RAN-UE-NGAP-ID

ProtocolIE-Field

id: id-RAN-UE-NGAP-ID (85)

criticality: reject (0)

value

RAN-UE-NGAP-ID: 1

Item 2: id-PDUSessionResourceSetupListSUReq

ProtocolIE-Field

id: id-PDUSessionResourceSetupListSUReq (74)

criticality: reject (0)

value

PDUSessionResourceSetupListSUReq: 1 item

Item 0

PDUSessionResourceSetupItemSUReq

pDUSessionID: 1

pDUSessionNAS-PDU: 7e02ba31020b097e006801

Non-Access-Stratum 5GS (NAS)PDU

Security protected NAS 5GS message

Extended protocol discriminator:

5G mobility management messages (126)

0000 .... = Spare Half Octet: 0

.... 0010 = Security header type:

Integrity protected and ciphered (2)

Message authentication code: 0xba31020b

Sequence number: 9

Encrypted data

s-NSSAI

sST: 01

pDUSessionResourceSetupRequestTransfer: 0000040082

PDUSessionResourceSetupRequestTransfer

protocolIEs: 4 items

Item 0: id-PDUSessionAggregateMaximumBitRate

ProtocolIE-Field

id: id-PDUSessionAggregateMaximumBitRate

criticality: reject (0)

value

PDUSessionAggregateMaximumBitRate

pDUSessionAggregateMaximumBitRateDL:

3000000000bits/s

pDUSessionAggregateMaximumBitRateUL:

1000000000bits/s

Item 1: id-UL-NGU-UP-TNLInformation

ProtocolIE-Field

id: id-UL-NGU-UP-TNLInformation (139)

criticality: reject (0)

value

UPTransportLayerInformation: gTPTunnel(0)

gTPTunnel

transportLayerAddress:

0a0000a2]

TransportLayerAddress

(IPv4): 10.0.0.162

gTP-TEID: 4f485cc3

Item 2: id-PDUSessionType

ProtocolIE-Field

id: id-PDUSessionType (134)

criticality: reject (0)

value

PDUSessionType: ipv4 (0)

Item 3: id-QosFlowSetupRequestList

ProtocolIE-Field

id: id-QosFlowSetupRequestList (136)

criticality: reject (0)

value

QosFlowSetupRequestList: 1 item

Item 0

QosFlowSetupRequestItem

qosFlowIdentifier: 1

qosFlowLevelQosParameters

qosCharacteristics:

nonDynamic5QI (0)

nonDynamic5QI

fiveQI: 9

allocationAndRetentionPriority

priorityLevelARP: 15

pre-emptionCapability:

shall-not-trigger-

pre-emption

preemptionVulnerability:

not-pre-emptable (0)

e-RAB-ID: 5

Item 3: id-UEAggregateMaximumBitRate

ProtocolIE-Field

id: id-UEAggregateMaximumBitRate (110)

criticality: ignore (1)

value

UEAggregateMaximumBitRate

uEAggregateMaximumBitRateDL: 3000000000bits/s

uEAggregateMaximumBitRateUL: 1000000000bits/s

(13) PDUSessionResourceSetupResponse

The PDUSessionResourceSetupResponse is sent by the gNodeB to the AMF as a reply to the PDUSessionResourceSetupRequest, indicating that the requested PDU session resources have been successfully set up or that there was an issue with the setup. The successful outcome of this message signifies that the gNodeB has allocated the necessary resources for the PDU session and is now ready for data transfer related to this specific session. The transport layer information included in the response is critical for routing the data packets to and from the UE.

This message contains the following information elements (IEs):

id-AMF-UE-NGAP-ID (Item 0): The unique identifier for the UE as known by the AMF, which in this case is 102. It is used to correlate the response with the correct UE context within the AMF.
id-RAN-UE-NGAP-ID (Item 1): The unique identifier for the UE as known by the RAN. This ID, 1 in this instance, is used by the gNodeB to track the UE's NGAP context.
id-PDUSessionResourceSetupListSURes (Item 2): A list indicating the results of the PDU session resource setup. It includes details for each PDU session that was part of the setup request:
pDUSessionID: The identifier for the PDU session, which is 1 here.
pDUSessionResourceSetupResponseTransfer: Contains the response for the PDU session resource setup.

dLQosFlowPerTNLInformation : Information on the transport layer and associated QoS flows. For instance, it provides the gTPTunnel information, including the IP address (10.0.0.185 in this example) and GTP-TEID (a968d0db in this example), which is used for tunneling user plane data.
associatedQosFlowList: : A list of QoS flows associated with the tunnel. Each QoS flow is identified by a qosFlowIdentifier.

Internet Protocol Version 4, Src: 10.0.0.185, Dst: 10.0.0.162

0100 .... = Version: 4

.... 0101 = Header Length: 20 bytes (5)

Differentiated Services Field: 0x02 (DSCP: CS0, ECN: ECT(0))

0000 00.. = Differentiated Services Codepoint: Default (0)

.... ..10 = Explicit Congestion Notification: ECN-Capable Transport codepoint '10' (2)

Total Length: 104

Identification: 0x0011 (17)

Flags: 0x40, Don't fragment

0... .... = Reserved bit: Not set

.1.. .... = Don't fragment: Set

..0. .... = More fragments: Not set

Fragment Offset: 0

Time to Live: 64

Protocol: SCTP (132)

Header Checksum: 0x24a5 [validation disabled]

[Header checksum status: Unverified]

Source Address: 10.0.0.185

Destination Address: 10.0.0.162

Stream Control Transmission Protocol, Src Port: 48041 (48041), Dst Port: 38412 (38412)

Source port: 48041

Destination port: 38412

Verification tag: 0x790ad620

[Association index: 65535]

Checksum: 0x1ef6563e [unverified]

[Checksum Status: Unverified]

SACK chunk (Cumulative TSN: 4169966871, a_rwnd: 106496, gaps: 0, duplicate TSNs: 0)

Chunk type: SACK (3)

0... .... = Bit: Stop processing of the packet

.0.. .... = Bit: Do not report

Chunk flags: 0x00

.... ...0 = Nounce sum: 0

Chunk length: 16

Cumulative TSN ACK: 4169966871

[Acknowledges TSN: 4169966871]

[Acknowledges TSN in frame: 911]

[The RTT since DATA was: 0.035658957 seconds]

Advertised receiver window credit (a_rwnd): 106496

Number of gap acknowledgement blocks: 0

Number of duplicated TSNs: 0

DATA chunk(ordered, complete segment, TSN: 3757580136, SID: 1, SSN: 6, PPID: 60,

payload length: 40 bytes)

Chunk type: DATA (0)

0... .... = Bit: Stop processing of the packet

.0.. .... = Bit: Do not report

Chunk flags: 0x03

.... 0... = I-Bit: Possibly delay SACK

.... .0.. = U-Bit: Ordered delivery

.... ..1. = B-Bit: First segment

.... ...1 = E-Bit: Last segment

Chunk length: 56

Transmission sequence number: 3757580136

[This chunk is acked in frame: 931]

[The RTT to SACK was: 0.201436229 seconds]

Stream identifier: 0x0001

Stream sequence number: 6

Payload protocol identifier: NGAP (60)

NG Application Protocol

NGAP-PDU: successfulOutcome (1)

successfulOutcome

procedureCode: id-PDUSessionResourceSetup (29)

criticality: reject (0)

value

PDUSessionResourceSetupResponse

protocolIEs: 3 items

Item 0: id-AMF-UE-NGAP-ID

ProtocolIE-Field

id: id-AMF-UE-NGAP-ID (10)

criticality: ignore (1)

value

AMF-UE-NGAP-ID: 102

Item 1: id-RAN-UE-NGAP-ID

ProtocolIE-Field

id: id-RAN-UE-NGAP-ID (85)

criticality: ignore (1)

value

RAN-UE-NGAP-ID: 1

Item 2: id-PDUSessionResourceSetupListSURes

ProtocolIE-Field

id: id-PDUSessionResourceSetupListSURes (75)

criticality: ignore (1)

value

PDUSessionResourceSetupListSURes: 1 item

Item 0

PDUSessionResourceSetupItemSURes

pDUSessionID: 1

pDUSessionResourceSetupResponseTransfer:

0003e00a0000b9a968d0db0001

PDUSessionResourceSetupResponseTransfer

dLQosFlowPerTNLInformation

uPTransportLayerInformation: gTPTunnel (0)

gTPTunnel

transportLayerAddress: 0a0000b9

TransportLayerAddress (IPv4):

10.0.0.185

gTP-TEID: a968d0db

associatedQosFlowList: 1 item

Item 0

AssociatedQosFlowItem

qosFlowIdentifier: 1

NGAP Messages/ASN

Here I am listing some of the NGAP messages that I personally come across most frequently. ASN structure is from 38.413 and Example messages are from Amarisoft Callbox log.

< NGSetupRequest>

NGSetupRequest ::= SEQUENCE {

protocolIEs ProtocolIE-Container { {NGSetupRequestIEs} },

...

}

NGSetupRequestIEs NGAP-PROTOCOL-IES ::= {

{ ID id-GlobalRANNodeID CRITICALITY reject TYPE GlobalRANNodeID PRESENCE mandatory }|

{ ID id-RANNodeName CRITICALITY ignore TYPE RANNodeName PRESENCE optional }|

{ ID id-SupportedTAList CRITICALITY reject TYPE SupportedTAList PRESENCE mandatory }|

{ ID id-DefaultPagingDRX CRITICALITY ignore TYPE PagingDRX PRESENCE mandatory }|

{ ID id-UERetentionInformation CRITICALITY ignore TYPE UERetentionInformation PRESENCE optional }|

{ ID id-NB-IoT-DefaultPagingDRX CRITICALITY ignore TYPE NB-IoT-DefaultPagingDRX PRESENCE optional }|

{ ID id-Extended-RANNodeName CRITICALITY ignore TYPE Extended-RANNodeName PRESENCE optional },

< Example 01 >

initiatingMessage: {

procedureCode id-NGSetup,

criticality reject,

value {

protocolIEs {

{

id id-GlobalRANNodeID,

criticality reject,

value globalGNB-ID: {

pLMNIdentity '00F110'H,

gNB-ID gNB-ID: '0012345'H

}

{

id id-RANNodeName,

criticality ignore,

value "gnb0012345"

{

id id-SupportedTAList,

criticality reject,

value {

{

tAC '000064'H,

broadcastPLMNList {

{

pLMNIdentity '00F110'H,

tAISliceSupportList {

{

s-NSSAI {

sST '01'H

}

{

id id-DefaultPagingDRX,

criticality ignore,

value v128

}

< NGSetupResponse>

NGSetupResponse ::= SEQUENCE {

protocolIEs ProtocolIE-Container { {NGSetupResponseIEs} },

...

}

NGSetupResponseIEs NGAP-PROTOCOL-IES ::= {

{ ID id-AMFName CRITICALITY reject TYPE AMFName PRESENCE mandatory }|

{ ID id-ServedGUAMIList CRITICALITY reject TYPE ServedGUAMIList PRESENCE mandatory }|

{ ID id-RelativeAMFCapacity CRITICALITY ignore TYPE RelativeAMFCapacity PRESENCE mandatory }|

{ ID id-PLMNSupportList CRITICALITY reject TYPE PLMNSupportList PRESENCE mandatory }|

{ ID id-CriticalityDiagnostics CRITICALITY ignore TYPE CriticalityDiagnostics PRESENCE optional }|

{ ID id-UERetentionInformation CRITICALITY ignore TYPE UERetentionInformation PRESENCE optional }|

{ ID id-IAB-Supported CRITICALITY ignore TYPE IAB-Supported PRESENCE optional }|

{ ID id-Extended-AMFName CRITICALITY ignore TYPE Extended-AMFName PRESENCE optional },

...

}

< Example 01 >

Message: 127.0.1.100:38412 NG setup response

Data:

successfulOutcome: {

procedureCode id-NGSetup,

criticality reject,

value {

protocolIEs {

{

id id-AMFName,

criticality reject,

value "amarisoft.amf.5gc.mnc001.mcc001.3gppnetwork.org"

{

id id-ServedGUAMIList,

criticality reject,

value {

{

gUAMI {

pLMNIdentity '00F110'H,

aMFRegionID '80'H,

aMFSetID '0000000100'B,

aMFPointer '000001'B

}

{

id id-RelativeAMFCapacity,

criticality ignore,

value 50

{

id id-PLMNSupportList,

criticality reject,

value {

{

pLMNIdentity '00F110'H,

sliceSupportList {

{

s-NSSAI {

sST '01'H

}

< UE Context Release >

InitiatingMessage ::= SEQUENCE {

procedureCode NGAP-ELEMENTARY-PROCEDURE.&procedureCode ({NGAP-ELEMENTARY-PROCEDURES}),

criticality NGAP-ELEMENTARY-PROCEDURE.&criticality ({NGAP-ELEMENTARY-PROCEDURES}{@procedureCode}),

value NGAP-ELEMENTARY-PROCEDURE.&InitiatingMessage ({NGAP-ELEMENTARY-PROCEDURES}{@procedureCode})

}

uEContextRelease NGAP-ELEMENTARY-PROCEDURE ::= {

INITIATING MESSAGE UEContextReleaseCommand

SUCCESSFUL OUTCOME UEContextReleaseComplete

PROCEDURE CODE id-UEContextRelease

CRITICALITY reject

}

UEContextReleaseCommand ::= SEQUENCE {

protocolIEs ProtocolIE-Container { {UEContextReleaseCommand-IEs} },

...

}

UEContextReleaseCommand-IEs NGAP-PROTOCOL-IES ::= {

{ ID id-UE-NGAP-IDs CRITICALITY reject TYPE UE-NGAP-IDs PRESENCE mandatory }|

{ ID id-Cause CRITICALITY ignore TYPE Cause PRESENCE mandatory },

...

}

UEContextReleaseComplete ::= SEQUENCE {

protocolIEs ProtocolIE-Container { {UEContextReleaseComplete-IEs} },

...

}

UEContextReleaseComplete-IEs NGAP-PROTOCOL-IES ::= {

{ ID id-AMF-UE-NGAP-ID CRITICALITY ignore TYPE AMF-UE-NGAP-ID PRESENCE mandatory }|

{ ID id-RAN-UE-NGAP-ID CRITICALITY ignore TYPE RAN-UE-NGAP-ID PRESENCE mandatory }|

{ ID id-UserLocationInformation CRITICALITY ignore TYPE UserLocationInformation PRESENCE optional }|

{ ID id-InfoOnRecommendedCellsAndRANNodesForPaging CRITICALITY ignore

TYPE InfoOnRecommendedCellsAndRANNodesForPaging PRESENCE optional }|

{ ID id-PDUSessionResourceListCxtRelCpl CRITICALITY reject

TYPE PDUSessionResourceListCxtRelCpl PRESENCE optional }|

{ ID id-CriticalityDiagnostics CRITICALITY ignore TYPE CriticalityDiagnostics PRESENCE optional }|

{ ID id-PagingAssisDataforCEcapabUE CRITICALITY ignore TYPE PagingAssisDataforCEcapabUE PRESENCE optional },

...

}

Cause ::= CHOICE {

radioNetwork CauseRadioNetwork,

transport CauseTransport,

nas CauseNas,

protocol CauseProtocol,

misc CauseMisc,

choice-Extensions ProtocolIE-SingleContainer { {Cause-ExtIEs} }

}

CauseRadioNetwork ::= ENUMERATED {

unspecified,

txnrelocoverall-expiry,

successful-handover,

release-due-to-ngran-generated-reason,

release-due-to-5gc-generated-reason,

handover-cancelled,

partial-handover,

ho-failure-in-target-5GC-ngran-node-or-target-system,

ho-target-not-allowed,

tngrelocoverall-expiry,

tngrelocprep-expiry,

cell-not-available,

unknown-targetID,

no-radio-resources-available-in-target-cell,

unknown-local-UE-NGAP-ID,

inconsistent-remote-UE-NGAP-ID,

handover-desirable-for-radio-reason,

time-critical-handover,

resource-optimisation-handover,

reduce-load-in-serving-cell,

user-inactivity,

radio-connection-with-ue-lost,

radio-resources-not-available,

invalid-qos-combination,

failure-in-radio-interface-procedure,

interaction-with-other-procedure,

unknown-PDU-session-ID,

unkown-qos-flow-ID,

multiple-PDU-session-ID-instances,

multiple-qos-flow-ID-instances,

encryption-and-or-integrity-protection-algorithms-not-supported,

ng-intra-system-handover-triggered,

ng-inter-system-handover-triggered,

xn-handover-triggered,

not-supported-5QI-value,

ue-context-transfer,

ims-voice-eps-fallback-or-rat-fallback-triggered,

up-integrity-protection-not-possible,

up-confidentiality-protection-not-possible,

slice-not-supported,

ue-in-rrc-inactive-state-not-reachable,

redirection,

resources-not-available-for-the-slice,

ue-max-integrity-protected-data-rate-reason,

release-due-to-cn-detected-mobility,

...,

n26-interface-not-available,

release-due-to-pre-emption,

multiple-location-reporting-reference-ID-instances,

rsn-not-available-for-the-up,

npn-access-denied,

cag-only-access-denied,

insufficient-ue-capabilities,

redcap-ue-not-supported,

unknown-MBS-Session-ID,

indicated-MBS-session-area-information-not-served-by-the-gNB,

inconsistent-slice-info-for-the-session,

misaligned-association-for-multicast-unicast

}

CauseTransport ::= ENUMERATED {

transport-resource-unavailable,

unspecified,

...

}

CauseNas ::= ENUMERATED {

normal-release,

authentication-failure,

deregister,

unspecified,

...,

uE-not-in-PLMN-serving-area

}

CauseProtocol ::= ENUMERATED {

transfer-syntax-error,

abstract-syntax-error-reject,

abstract-syntax-error-ignore-and-notify,

message-not-compatible-with-receiver-state,

semantic-error,

abstract-syntax-error-falsely-constructed-message,

unspecified,

...

}

CauseMisc ::= ENUMERATED {

control-processing-overload,

not-enough-user-plane-processing-resources,

hardware-failure,

om-intervention,

unknown-PLMN-or-SNPN,

unspecified,

...

}

< Example 01 >

initiatingMessage: {

procedureCode id-UEContextRelease,

criticality reject,

value {

protocolIEs {

{

id id-UE-NGAP-IDs,

criticality reject,

value uE-NGAP-ID-pair: {

aMF-UE-NGAP-ID 100,

rAN-UE-NGAP-ID 1

}

{

id id-Cause,

criticality ignore,

value radioNetwork: user-inactivity

}

< InitialContextSetupRequest>

InitialContextSetupRequest ::= SEQUENCE {

protocolIEs ProtocolIE-Container { {InitialContextSetupRequestIEs} },

...

}

InitialContextSetupRequestIEs NGAP-PROTOCOL-IES ::= {

{ ID id-AMF-UE-NGAP-ID CRITICALITY reject TYPE AMF-UE-NGAP-ID PRESENCE mandatory }|

{ ID id-RAN-UE-NGAP-ID CRITICALITY reject TYPE RAN-UE-NGAP-ID PRESENCE mandatory }|

{ ID id-OldAMF CRITICALITY reject TYPE AMFName PRESENCE optional }|

{ ID id-UEAggregateMaximumBitRate CRITICALITY reject TYPE UEAggregateMaximumBitRate PRESENCE conditional }|

{ ID id-CoreNetworkAssistanceInformationForInactive CRITICALITY ignore

TYPE CoreNetworkAssistanceInformationForInactive PRESENCE optional }|

{ ID id-GUAMI CRITICALITY reject TYPE GUAMI PRESENCE mandatory }|

{ ID id-PDUSessionResourceSetupListCxtReq CRITICALITY reject TYPE PDUSessionResourceSetupListCxtReq PRESENCE optional }|

{ ID id-AllowedNSSAI CRITICALITY reject TYPE AllowedNSSAI PRESENCE mandatory }|

{ ID id-UESecurityCapabilities CRITICALITY reject TYPE UESecurityCapabilities PRESENCE mandatory }|

{ ID id-SecurityKey CRITICALITY reject TYPE SecurityKey PRESENCE mandatory }|

{ ID id-TraceActivation CRITICALITY ignore TYPE TraceActivation PRESENCE optional }|

{ ID id-MobilityRestrictionList CRITICALITY ignore TYPE MobilityRestrictionList PRESENCE optional }|

{ ID id-UERadioCapability CRITICALITY ignore TYPE UERadioCapability PRESENCE optional }|

{ ID id-IndexToRFSP CRITICALITY ignore TYPE IndexToRFSP PRESENCE optional }|

{ ID id-MaskedIMEISV CRITICALITY ignore TYPE MaskedIMEISV PRESENCE optional }|

{ ID id-NAS-PDU CRITICALITY ignore TYPE NAS-PDU PRESENCE optional }|

{ ID id-EmergencyFallbackIndicator CRITICALITY reject TYPE EmergencyFallbackIndicator PRESENCE optional }|

{ ID id-RRCInactiveTransitionReportRequest CRITICALITY ignore

TYPE RRCInactiveTransitionReportRequest PRESENCE optional }|

{ ID id-UERadioCapabilityForPaging CRITICALITY ignore TYPE UERadioCapabilityForPaging PRESENCE optional }|

{ ID id-RedirectionVoiceFallback CRITICALITY ignore TYPE RedirectionVoiceFallback PRESENCE optional }|

{ ID id-LocationReportingRequestType CRITICALITY ignore TYPE LocationReportingRequestType PRESENCE optional }|

{ ID id-CNAssistedRANTuning CRITICALITY ignore TYPE CNAssistedRANTuning PRESENCE optional }|

{ ID id-SRVCCOperationPossible CRITICALITY ignore TYPE SRVCCOperationPossible PRESENCE optional }|

{ ID id-IAB-Authorized CRITICALITY ignore TYPE IAB-Authorized PRESENCE optional }|

{ ID id-Enhanced-CoverageRestriction CRITICALITY ignore TYPE Enhanced-CoverageRestriction PRESENCE optional }|

{ ID id-Extended-ConnectedTime CRITICALITY ignore TYPE Extended-ConnectedTime PRESENCE optional }|

{ ID id-UE-DifferentiationInfo CRITICALITY ignore TYPE UE-DifferentiationInfo PRESENCE optional }|

{ ID id-NRV2XServicesAuthorized CRITICALITY ignore TYPE NRV2XServicesAuthorized PRESENCE optional }|

{ ID id-LTEV2XServicesAuthorized CRITICALITY ignore TYPE LTEV2XServicesAuthorized PRESENCE optional }|

{ ID id-NRUESidelinkAggregateMaximumBitrate CRITICALITY ignore

TYPE NRUESidelinkAggregateMaximumBitrate PRESENCE optional }|

{ ID id-LTEUESidelinkAggregateMaximumBitrate CRITICALITY ignore

TYPE LTEUESidelinkAggregateMaximumBitrate PRESENCE optional }|

{ ID id-PC5QoSParameters CRITICALITY ignore TYPE PC5QoSParameters PRESENCE optional }|

{ ID id-CEmodeBrestricted CRITICALITY ignore TYPE CEmodeBrestricted PRESENCE optional }|

{ ID id-UE-UP-CIoT-Support CRITICALITY ignore TYPE UE-UP-CIoT-Support PRESENCE optional }|

{ ID id-RGLevelWirelineAccessCharacteristics CRITICALITY ignore

TYPE RGLevelWirelineAccessCharacteristics PRESENCE optional }|

{ ID id-ManagementBasedMDTPLMNList CRITICALITY ignore TYPE MDTPLMNList PRESENCE optional }|

{ ID id-UERadioCapabilityID CRITICALITY reject TYPE UERadioCapabilityID PRESENCE optional }|

{ ID id-TimeSyncAssistanceInfo CRITICALITY ignore TYPE TimeSyncAssistanceInfo PRESENCE optional }|

{ ID id-QMCConfigInfo CRITICALITY ignore TYPE QMCConfigInfo PRESENCE optional }|

{ ID id-TargetNSSAIInformation CRITICALITY ignore TYPE TargetNSSAIInformation PRESENCE optional }|

{ ID id-UESliceMaximumBitRateList CRITICALITY ignore TYPE UESliceMaximumBitRateList PRESENCE optional }|

{ ID id-FiveG-ProSeAuthorized CRITICALITY ignore TYPE FiveG-ProSeAuthorized PRESENCE optional }|

{ ID id-FiveG-ProSeUEPC5AggregateMaximumBitRate CRITICALITY ignore

TYPE NRUESidelinkAggregateMaximumBitrate PRESENCE optional }|

{ ID id-FiveG-ProSePC5QoSParameters CRITICALITY ignore

TYPE FiveG-ProSePC5QoSParameters PRESENCE optional },

...

}

< InitialContextSetupResponse >

InitialContextSetupResponse ::= SEQUENCE {

protocolIEs ProtocolIE-Container { {InitialContextSetupResponseIEs} },

...

}

InitialContextSetupResponseIEs NGAP-PROTOCOL-IES ::= {

{ ID id-AMF-UE-NGAP-ID CRITICALITY ignore TYPE AMF-UE-NGAP-ID PRESENCE mandatory }|

{ ID id-RAN-UE-NGAP-ID CRITICALITY ignore TYPE RAN-UE-NGAP-ID PRESENCE mandatory }|

{ ID id-PDUSessionResourceSetupListCxtRes CRITICALITY ignore

TYPE PDUSessionResourceSetupListCxtRes PRESENCE optional }|

{ ID id-PDUSessionResourceFailedToSetupListCxtRes CRITICALITY ignore

TYPE PDUSessionResourceFailedToSetupListCxtRes PRESENCE optional }|

{ ID id-CriticalityDiagnostics CRITICALITY ignore TYPE CriticalityDiagnostics PRESENCE optional},

...

}

PDUSessionResourceSetupListCxtRes ::= SEQUENCE (SIZE(1..maxnoofPDUSessions))

OF PDUSessionResourceSetupItemCxtRes

PDUSessionResourceSetupItemCxtRes ::= SEQUENCE {

pDUSessionID PDUSessionID,

pDUSessionResourceSetupResponseTransfer OCTET STRING

(CONTAINING PDUSessionResourceSetupResponseTransfer),

iE-Extensions ProtocolExtensionContainer { {PDUSessionResourceSetupItemCxtRes-ExtIEs} } OPTIONAL,

...

}

PDUSessionResourceSetupResponseTransfer ::= SEQUENCE {

dLQosFlowPerTNLInformation QosFlowPerTNLInformation,

additionalDLQosFlowPerTNLInformation QosFlowPerTNLInformationList OPTIONAL,

securityResult SecurityResult OPTIONAL,

qosFlowFailedToSetupList QosFlowListWithCause OPTIONAL,

iE-Extensions ProtocolExtensionContainer { {PDUSessionResourceSetupResponseTransfer-ExtIEs} } OPTIONAL,

...

}

PDUSessionResourceSetupResponseTransfer-ExtIEs NGAP-PROTOCOL-EXTENSION ::= {

{ ID id-RedundantDLQosFlowPerTNLInformation CRITICALITY ignore

EXTENSION QosFlowPerTNLInformation PRESENCE optional }|

{ ID id-AdditionalRedundantDLQosFlowPerTNLInformation CRITICALITY ignore

EXTENSION QosFlowPerTNLInformationList PRESENCE optional }|

{ ID id-UsedRSNInformation CRITICALITY ignore EXTENSION RedundantPDUSessionInformation PRESENCE optional }|

{ ID id-GlobalRANNodeID CRITICALITY ignore EXTENSION GlobalRANNodeID PRESENCE optional }|

{ ID id-MBS-SupportIndicator CRITICALITY ignore EXTENSION MBS-SupportIndicator PRESENCE optional }|

{ ID id-MBSSessionSetupResponseList CRITICALITY ignore

EXTENSION MBSSessionSetupResponseList PRESENCE optional }|

{ ID id-MBSSessionFailedtoSetupList CRITICALITY ignore

EXTENSION MBSSessionFailedtoSetupList PRESENCE optional },

...

}

< InitialUEMessage >

InitialUEMessage ::= SEQUENCE {

protocolIEs ProtocolIE-Container { {InitialUEMessage-IEs} },

...

}

InitialUEMessage-IEs NGAP-PROTOCOL-IES ::= {

{ ID id-RAN-UE-NGAP-ID CRITICALITY reject TYPE RAN-UE-NGAP-ID PRESENCE mandatory }|

{ ID id-NAS-PDU CRITICALITY reject TYPE NAS-PDU PRESENCE mandatory }|

{ ID id-UserLocationInformation CRITICALITY reject TYPE UserLocationInformation PRESENCE mandatory }|

{ ID id-RRCEstablishmentCause CRITICALITY ignore TYPE RRCEstablishmentCause PRESENCE mandatory }|

{ ID id-FiveG-S-TMSI CRITICALITY reject TYPE FiveG-S-TMSI PRESENCE optional }|

{ ID id-AMFSetID CRITICALITY ignore TYPE AMFSetID PRESENCE optional }|

{ ID id-UEContextRequest CRITICALITY ignore TYPE UEContextRequest PRESENCE optional }|

{ ID id-AllowedNSSAI CRITICALITY reject TYPE AllowedNSSAI PRESENCE optional }|

{ ID id-SourceToTarget-AMFInformationReroute CRITICALITY ignore

TYPE SourceToTarget-AMFInformationReroute PRESENCE optional }|

{ ID id-SelectedPLMNIdentity CRITICALITY ignore TYPE PLMNIdentity PRESENCE optional }|

{ ID id-IABNodeIndication CRITICALITY reject TYPE IABNodeIndication PRESENCE optional }|

{ ID id-CEmodeBSupport-Indicator CRITICALITY reject TYPE CEmodeBSupport-Indicator PRESENCE optional }|

{ ID id-LTEM-Indication CRITICALITY ignore TYPE LTEM-Indication PRESENCE optional }|

{ ID id-EDT-Session CRITICALITY ignore TYPE EDT-Session PRESENCE optional }|

{ ID id-AuthenticatedIndication CRITICALITY ignore TYPE AuthenticatedIndication PRESENCE optional }|

{ ID id-NPN-AccessInformation CRITICALITY reject TYPE NPN-AccessInformation PRESENCE optional }|

{ ID id-RedCapIndication CRITICALITY ignore TYPE RedCapIndication PRESENCE optional },

...

}

< UEContextModificationRequest >

UEContextModificationRequest ::= SEQUENCE {

protocolIEs ProtocolIE-Container { {UEContextModificationRequestIEs} },

...

}

UEContextModificationRequestIEs NGAP-PROTOCOL-IES ::= {

{ ID id-AMF-UE-NGAP-ID CRITICALITY reject TYPE AMF-UE-NGAP-ID PRESENCE mandatory }|

{ ID id-RAN-UE-NGAP-ID CRITICALITY reject TYPE RAN-UE-NGAP-ID PRESENCE mandatory }|

{ ID id-RANPagingPriority CRITICALITY ignore TYPE RANPagingPriority PRESENCE optional }|

{ ID id-SecurityKey CRITICALITY reject TYPE SecurityKey PRESENCE optional }|

{ ID id-IndexToRFSP CRITICALITY ignore TYPE IndexToRFSP PRESENCE optional }|

{ ID id-UEAggregateMaximumBitRate CRITICALITY ignore TYPE UEAggregateMaximumBitRate PRESENCE optional }|

{ ID id-UESecurityCapabilities CRITICALITY reject TYPE UESecurityCapabilities PRESENCE optional }|

{ ID id-CoreNetworkAssistanceInformationForInactive CRITICALITY ignore TYPE

CoreNetworkAssistanceInformationForInactive PRESENCE optional }|

{ ID id-EmergencyFallbackIndicator CRITICALITY reject TYPE EmergencyFallbackIndicator PRESENCE optional }|

{ ID id-NewAMF-UE-NGAP-ID CRITICALITY reject TYPE AMF-UE-NGAP-ID PRESENCE optional }|

{ ID id-RRCInactiveTransitionReportRequest CRITICALITY ignore TYPE RRCInactiveTransitionReportRequest

PRESENCE optional }|

{ ID id-NewGUAMI CRITICALITY reject TYPE GUAMI PRESENCE optional }|

{ ID id-CNAssistedRANTuning CRITICALITY ignore TYPE CNAssistedRANTuning PRESENCE optional }|

{ ID id-SRVCCOperationPossible CRITICALITY ignore TYPE SRVCCOperationPossible PRESENCE optional }|

{ ID id-IAB-Authorized CRITICALITY ignore TYPE IAB-Authorized PRESENCE optional }|

{ ID id-NRV2XServicesAuthorized CRITICALITY ignore TYPE NRV2XServicesAuthorized PRESENCE optional }|

{ ID id-LTEV2XServicesAuthorized CRITICALITY ignore TYPE LTEV2XServicesAuthorized PRESENCE optional }|

{ ID id-NRUESidelinkAggregateMaximumBitrate CRITICALITY ignore TYPE NRUESidelinkAggregateMaximumBitrate

PRESENCE optional }|

{ ID id-LTEUESidelinkAggregateMaximumBitrate CRITICALITY ignore TYPE LTEUESidelinkAggregateMaximumBitrate

PRESENCE optional }|

{ ID id-PC5QoSParameters CRITICALITY ignore TYPE PC5QoSParameters PRESENCE optional }|

{ ID id-UERadioCapabilityID CRITICALITY reject TYPE UERadioCapabilityID PRESENCE optional }|

{ ID id-RGLevelWirelineAccessCharacteristics CRITICALITY ignore TYPE RGLevelWirelineAccessCharacteristics

PRESENCE optional }|

{ ID id-TimeSyncAssistanceInfo CRITICALITY ignore TYPE TimeSyncAssistanceInfo PRESENCE optional }|

{ ID id-QMCConfigInfo CRITICALITY ignore TYPE QMCConfigInfo PRESENCE optional }|

{ ID id-QMCDeactivation CRITICALITY ignore TYPE QMCDeactivation PRESENCE optional }|

{ ID id-UESliceMaximumBitRateList CRITICALITY ignore TYPE UESliceMaximumBitRateList PRESENCE optional }|

{ ID id-ManagementBasedMDTPLMNModificationList CRITICALITY ignore TYPE MDTPLMNModificationList

PRESENCE optional }|

{ ID id-FiveG-ProSeAuthorized CRITICALITY ignore TYPE FiveG-ProSeAuthorized PRESENCE optional }|

{ ID id-FiveG-ProSeUEPC5AggregateMaximumBitRate CRITICALITY ignore TYPE NRUESidelinkAggregateMaximumBitrate

PRESENCE optional }|

{ ID id-FiveG-ProSePC5QoSParameters CRITICALITY ignore TYPE FiveG-ProSePC5QoSParameters PRESENCE optional},

< UEContextModificationResponse >

UEContextModificationResponse ::= SEQUENCE {

protocolIEs ProtocolIE-Container { {UEContextModificationResponseIEs} },

...

}

UEContextModificationResponseIEs NGAP-PROTOCOL-IES ::= {

{ ID id-AMF-UE-NGAP-ID CRITICALITY ignore TYPE AMF-UE-NGAP-ID PRESENCE mandatory }|

{ ID id-RAN-UE-NGAP-ID CRITICALITY ignore TYPE RAN-UE-NGAP-ID PRESENCE mandatory }|

{ ID id-RRCState CRITICALITY ignore TYPE RRCState PRESENCE optional }|

{ ID id-UserLocationInformation CRITICALITY ignore TYPE UserLocationInformation PRESENCE optional }|

{ ID id-CriticalityDiagnostics CRITICALITY ignore TYPE CriticalityDiagnostics PRESENCE optional },

...

}