4G/LTE - IDs

 

 

 

 

IDs in LTE

 

Celluar Network including LTE has very complicated structure and it is made up of may different layers. In addition, the network is communicating with many different user (UEs) at the same time. So if you pick any one point along the network architecture and observe the traffic following in and out of the point, it is highly likely that many traffics for multiple users are following through the point. In this situation, how each of the network components can figure out which traffic is for which UE. Also when the traffic gets transmitted onto the air, each UE is recieving all the physical layer data not only for itself but also for other UE. In this case how UE can figure out which data it has to decode and which data it has to discard.  

To solve this issues, we use specific IDs. But in many cases different network components uses different types of IDs even for the same UE and same data. For example, even for the same data and the same UE, the type of IDs between UE and eNB and type of IDs on X2, S1, S5 interfaces may be different. So it will be very difficult and very confusing to follow through a single traffic from a UE to final destination. Also, when you are discussing with other people about the traffic and IDs, you may easily confuse others (sometimes confuse yourself :)) if you don't specify exact point along the overall data path and explicitely mention on your intention of the discussion.

 

Before you read through this page, I recommend you to go through the diagram at this link LTE-Identifier and get a big picture on what kind of ID is used at each point on overall data path. In this page, I will keep adding specific details of each IDs and examples of real signaling message so that you can use this page as a dictionary of IDs. (This is very beginning, so please don't expect the complete dictionary for now :))

 

Note : Following table is based on the document from MNC Group (LTE-Identifier)

ID

Meaning

Description

Structure

IMSI

International Mobile Subscriber Identity

Unique identification of mobile (LTE) subscriber Network (MME) gets the PLMN of the subscriber

IMSI (not more than 15 digits) = PLMN ID + MSIN = MCC + MNC + MSIN

PLMN ID

Public Land Mobile Network Identifier

Unique identification of PLMN

PLMN ID (not more than 6 digits) = MCC + MNC

MCC

Mobile Country Code

assigned by ITU

3 digits

MNC

Mobile Network Code

assigned by National Authority

2 or 3 digits

MSIN

Mobile Subscriber Identification Number

assigned by operator

9 or 10 digits

GUTI

Globally Unique Temporary UE Identity

To identify a UE between the UE and the MME on behalf of IMSI for security reason

GUTI (not more than 80 bits) = GUMMEI + M-TMSI

TIN

Temporary Identity used in Next Update

GUTI is stored in TIN parameter of UE’s MM context. TIN indicates which temporary ID will be used in the next update.

TIN = GUTI

S-TMSI

SAE Temporary Mobile Subscriber Identity

To locally identify a UE in short within a MME group (Unique within a MME Pool)

S-TMSI (40 bits) = MMEC + M-TMSI

M-TMSI

MME Mobile Subscriber Identity

Unique within a MME

32 bits

GUMMEI

Globally Unique MME Identity

To identify a MME uniquely in global

GUTI contains GUMMEI

GUMMEI (not more than 48 bits)= PLMN ID + MMEI

MMEI

MME Identifier

To identify a MME uniquely within a PLMN

Operator commissions at eNBMMEI

MMEI (24 bits) = MMEGI + MMEC

MMEGI

MME Group Identifier

Unique within a PLMN

16 bits

MMEC

MME Code

To identify a MME uniquely within a MME Group. S-TMSI contains MMEC8

8 bits

C-RNTI

Cell- Radio Network Temporary Identifier

To identify an UE uniquely in a cell

0x0001 ~ 0xFFF3 (16 bits)

IMEI

International Mobile Equipment Identity

To identify a ME (Mobile Equipment) uniquely

IMEI (15 digits) = TAC + SNR + CD

IMEI/SV

IMEI/Software Version

To identify a ME (Mobile Equipment) uniquely

IMEI/SV (16 digits) = TAC + SNR + SVN

ECGI

E-UTRAN Cell Global Identifier

To identify a Cell in global (Globally Unique)

EPC can know UE location based of ECGI

ECGI (not more than 52 bits) = PLMN I D+ ECI

ECI

E-UTRAN Cell Identifier

To identify a Cell within a PLMN

ECI (28 Bits) = eNB ID + Cell ID

PGW ID

PDN GW Identity

To identify a specific PDN GW (P-GW)

HSS assigns P-GW for PDN (IP network) connection of each UE

IP address (4 bytes) or FQDN (variable length)

TAI

Tracking Area Identity

To identify Tracking Area

Globally uniqueTAI

TAI (not more than 32 bits) = PLMN ID + TAC P-GW

TAC

Tracking Area Code

To indicate eNB to which Tracking Area the eNB belongs (per Cell)

Unique within a PLMN16

16 bits

TAI List

Tracking Area Identity List

UE can move into the cells included in TAL list without location update (TA update)

Globally unique

Variable length
PDN ID

Packet Data Network Identity

To identify an PDN (IP network), that mobile data user wants to communicate with

PDN Identity (APN) is used to determine the P-GW and point of interconnection with a PDN

With APN as query parameter to the DNS procedures, the MME will receive a list of candidate P-GWs, and then a P-GW is selected by MME with policy

PDN Identify = APN = APN.NI + APN.OI (variable length)

EPS Bearer ID

Evolved Packet System Bearer Identifier

To identify an EPS bearer (Default or Dedicated) per an UE4

4 bits

E-RAB ID

E-UTRAN Radio Access Bearer Identifier•

To identify an E-RAB per an UE

4 bits

DRB ID

Data Radio Bearer Identifier

To identify a DRB per an UE4

4 bits

LBI

Linked EPS Bearer ID

To identify the default bearer associated with a dedicated EPS bearer4

4 bits

TEID

Tunnel End Point identifier

To identify the end point of a GTP tunnel when the tunnel is established

32 bits

 

 

PLMN/CellID in SIB1

 

This is a RRC OTA (Over the air) message between UE and eNB.

 

 

 

MME IDs

 

This is a NAS OTA (Over the air) message between UE and eNB. (These messages are usually embedded into a RRC message. For example, Attach Request would be embedded in RRC Connection Setup Complete and Attach Accept would be embedded in RRC Connection Reconfiguration message. Refer to here for full message example)

 

 

 

 

M-TMSI

 

This is a NAS OTA (Over the air) message between UE and eNB. (These messages are usually embedded into a RRC message. For example, Attach Request would be embedded in RRC Connection Setup Complete and Attach Accept would be embedded in RRC Connection Reconfiguration message. Refer to here for full message example)

 

 

 

 

TEID

 

Followings are some examples of TEID in S1AP messages. I made visible some other types of IDs as well for your reference.

 

S1 Application Protocol

    S1AP-PDU: initiatingMessage (0)

        initiatingMessage

            procedureCode: id-InitialContextSetup (9)

            criticality: reject (0)

            value

                InitialContextSetupRequest

                    protocolIEs: 8 items

                        Item 0: id-MME-UE-S1AP-ID

                            ProtocolIE-Field

                                id: id-MME-UE-S1AP-ID (0)

                                criticality: reject (0)

                                value

                                    MME-UE-S1AP-ID: 285212685

                        Item 1: id-eNB-UE-S1AP-ID

                            ProtocolIE-Field

                                id: id-eNB-UE-S1AP-ID (8)

                                criticality: reject (0)

                                value

                                    ENB-UE-S1AP-ID: 3

                        Item 2: id-uEaggregateMaximumBitrate

                        Item 3: id-E-RABToBeSetupListCtxtSUReq

                            ProtocolIE-Field

                                id: id-E-RABToBeSetupListCtxtSUReq (24)

                                criticality: reject (0)

                                value

                                    E-RABToBeSetupListCtxtSUReq: 1 item

                                        Item 0: id-E-RABToBeSetupItemCtxtSUReq

                                            ProtocolIE-SingleContainer

                                                id: id-E-RABToBeSetupItemCtxtSUReq (52)

                                                criticality: reject (0)

                                                value

                                                    E-RABToBeSetupItemCtxtSUReq

                                                        e-RAB-ID: 5

                                                        e-RABlevelQoSParameters

                                                            qCI: 9

                                                            allocationRetentionPriority

                                                                ...

                                                      transportLayerAddress: 12345678 ...

                                                        gTP-TEID: 12345678

                                                        ...

                                                            EPS mobile identity - GUTI

                                                                Element ID: 0x50

                                                                Length: 11

                                                                .... 0... = odd/even indic: 0

                                                                .... .110 = Type of identity: GUTI

                                                                Mobile Country Code (MCC): 001

                                                                Mobile Network Code (MNC): 01

                                                                MME Group ID: 12345

                                                                MME Code: 12

                                                                M-TMSI: 0x12345678

                                                            ....

                        Item 4: ...

 

 

GPRS Tunneling Protocol

    Flags: 0x30

        001. .... = Version: GTP release 99 version (1)

        ...1 .... = Protocol type: GTP (1)

        .... 0... = Reserved: 0

        .... .0.. = Is Next Extension Header present?: No

        .... ..0. = Is Sequence Number present?: No

        .... ...0 = Is N-PDU number present?: No

    Message Type: T-PDU (0xff)

    Length: 59

    TEID: 0x12345678

    T-PDU Data: 450000....

 

 

EUTRAN X2 Application Protocol (X2AP)

    X2AP-PDU: initiatingMessage (0)

        initiatingMessage

            procedureCode: id-handoverPreparation (0)

            criticality: reject (0)

            value

                HandoverRequest

                    protocolIEs: 6 items

                        Item 0: id-Old-eNB-UE-X2AP-ID

                            ProtocolIE-Field

                                id: id-Old-eNB-UE-X2AP-ID (10)

                                criticality: reject (0)

                                value

                                    UE-X2AP-ID: 2

                        Item 1: id-Cause

                            ProtocolIE-Field

                                id: id-Cause (5)

                                criticality: ignore (1)

                                value

                                    Cause: radioNetwork (0)

                                        radioNetwork: handover-desirable-for-radio-reasons (0)

                        Item 2: id-TargetCell-ID

                            ProtocolIE-Field

                                id: id-TargetCell-ID (11)

                                criticality: reject (0)

                                value

                                    ECGI

                                        pLMN-Identity: 123456

                                        Mobile Country Code (MCC): 001

                                        Mobile Network Code (MNC): 01

                                        eUTRANcellIdentifier: 12345678

                        Item 3: id-GUMMEI-ID

                            ProtocolIE-Field

                                id: id-GUMMEI-ID (23)

                                criticality: reject (0)

                                value

                                    GUMMEI

                                        gU-Group-ID

                                            pLMN-Identity: 123456

                                            Mobile Country Code (MCC): 001

                                            Mobile Network Code (MNC): 01

                                            mME-Group-ID: 1234

                                        mME-Code: 21

                        Item 4: id-UE-ContextInformation

                            ProtocolIE-Field

                                id: id-UE-ContextInformation (14)

                                criticality: reject (0)

                                value

                                    UE-ContextInformation

                                        ...

                                        e-RABs-ToBeSetup-List: 1 item

                                            Item 0: id-E-RABs-ToBeSetup-Item

                                                ProtocolIE-Single-Container

                                                    id: id-E-RABs-ToBeSetup-Item (4)

                                                    criticality: ignore (1)

                                                    value

                                                        E-RABs-ToBeSetup-Item

                                                            e-RAB-ID: 5

                                                            e-RAB-Level-QoS-Parameters

                                                            ...

                                                            uL-GTPtunnelEndpoint

                                                                ...

                                                                transportLayerAddress: xxxxxxxx

                                                                    transportLayerAddress(IPv4):

                                                                                   xxx.xxx.xxx.xxx

                                                                gTP-TEID: 12345678

                                        rRC-Context: < RRC HEX >...

                                        HandoverPreparationInformation

                                            criticalExtensions: c1 (0)

                                                c1: handoverPreparationInformation-r8 (0)

                                                    handoverPreparationInformation-r8

                                                        ue-RadioAccessCapabilityInfo: 1 item

                                                            Item 0

                                                                UE-CapabilityRAT-Container

                                                                    rat-Type: eutra (0)

                                                                    ueCapabilityRAT-Container:

                                                                                 < Hex String >...

                                                                        

                                                        as-Config

                                                            ...                    

                        Item 5: id-UE-HistoryInformation

                            ProtocolIE-Field

                                id: id-UE-HistoryInformation (15)

                                criticality: ignore (1)

                                value

                                    UE-HistoryInformation: 1 item

                                        Item 0

                                            LastVisitedCell-Item: e-UTRAN-Cell (0)

                                                e-UTRAN-Cell

                                                    global-Cell-ID

                                                        pLMN-Identity: 123456

                                                        Mobile Country Code (MCC): 001

                                                        Mobile Network Code (MNC): 01

                                                        eUTRANcellIdentifier: 12345678

                                                    cellType

                                                        cell-Size: small (1)

                                                    time-UE-StayedInCell: 11

 

 

Followings are some examples of TEID in X2AP messages. I made visible some other types of IDs as well for your reference.

 

EUTRAN X2 Application Protocol (X2AP)

    X2AP-PDU: successfulOutcome (1)

        successfulOutcome

            procedureCode: id-handoverPreparation (0)

            criticality: reject (0)

            value

                HandoverRequestAcknowledge

                    protocolIEs: 4 items

                        Item 0: id-Old-eNB-UE-X2AP-ID

                            ProtocolIE-Field

                                id: id-Old-eNB-UE-X2AP-ID (10)

                                criticality: ignore (1)

                                value

                                    UE-X2AP-ID: 2

                        Item 1: id-New-eNB-UE-X2AP-ID

                            ProtocolIE-Field

                                id: id-New-eNB-UE-X2AP-ID (9)

                                criticality: ignore (1)

                                value

                                    UE-X2AP-ID: 1

                        Item 2: id-E-RABs-Admitted-List

                            ProtocolIE-Field

                                id: id-E-RABs-Admitted-List (1)

                                criticality: ignore (1)

                                value

                                    E-RABs-Admitted-List: 1 item

                                        Item 0: id-E-RABs-Admitted-Item

                                            ProtocolIE-Single-Container

                                                id: id-E-RABs-Admitted-Item (0)

                                                criticality: ignore (1)

                                                value

                                                    E-RABs-Admitted-Item

                                                        e-RAB-ID: 5

                                                        uL-GTP-TunnelEndpoint

                                                            ...0 .... Extension Present Bit: False

                                                            transportLayerAddress: xxxxxxxx

                                                                transportLayerAddress(IPv4):

                                                                                 xxx.xxx.xxx.xxx

                                                            gTP-TEID: 12345678

                                                        dL-GTP-TunnelEndpoint

                                                            ..0. .... Extension Present Bit: False

                                                            transportLayerAddress: xxxxxxxx

                                                                transportLayerAddress(IPv4):

                                                                                 xxx.xxx.xxx.xxx

                                                            gTP-TEID: 12345678

                        Item 3: id-TargeteNBtoSource-eNBTransparentContainer

                            ProtocolIE-Field

                                id: id-TargeteNBtoSource-eNBTransparentContainer (12)

                                criticality: ignore (1)

                                value

                                    TargeteNBtoSource-eNBTransparentContainer: < Hex String ...>

                                    HandoverCommand

                                        criticalExtensions: c1 (0)

                                            c1: handoverCommand-r8 (0)

                                                handoverCommand-r8

                                                    handoverCommandMessage: < Hex String ...>

                                                        DL-DCCH-Message

                                                            message: c1 (0)

                                                                ....

 

 

DRB-ID

 

Following is RRC Connection Reconfiguration message sent from eNB to UE. DRB ID is marked in Red and some other IDs are also marked in blue for your reference.

 

c1: rrcConnectionReconfiguration-r8 (0)

    rrcConnectionReconfiguration-r8

        dedicatedInfoNASList: 1 item

            Item 0

                DedicatedInfoNAS: 27f9574e50056200c5050501010101011722300008404a12...

                    Non-Access-Stratum (NAS)PDU

                        0010 .... = Security header type: Integrity protected and ciphered (2)

                        .... 0111 = Protocol discriminator: EPS mobility management messages (0x07)

                        Message authentication code: 0xf9574e50

                        Sequence number: 5

                        0110 .... = EPS bearer identity: EPS bearer identity value 6 (6)

                        .... 0010 = Protocol discriminator: EPS session management messages (0x02)

                        Procedure transaction identity: 0

                        NAS EPS session management messages:

                                    Activate dedicated EPS bearer context request (0xc5)

                        0000 .... = Spare half octet: 0

                        .... 0101 = Linked EPS bearer identity: EPS bearer identity value 5 (5)

                        EPS quality of service

                            Length: 5

                            Quality of Service Class Identifier (QCI): QCI 1 (1)

                            ...

                        Traffic Flow Template

                            Length: 23

                            001. .... = TFT operation code: Create new TFT (1)

                            ...0 .... = E bit: Parameters list is not included

                            .... 0010 = Number of packet filters: 2

                            Packet filter: 0

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

                                ..11 .... = Packet filter direction: Bidirectional (3)

                                .... 0000 = Packet filter identifier: 1 (0)

                                ....

                            Packet filter: 1

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

                                ..11 .... = Packet filter direction: Bidirectional (3)

                                .... 0001 = Packet filter identifier: 2 (1)

                                ....

        radioResourceConfigDedicated

                drb-ToAddModList: 1 item

                Item 0

                   DRB-ToAddMod

                        eps-BearerIdentity: 6

                        drb-Identity: 2

                        pdcp-Config

                            discardTimer: infinity (7)

                            rlc-UM

                                pdcp-SN-Size: len12bits (1)

                            headerCompression: notUsed (0)

                                notUsed: NULL

                        rlc-Config: um-Bi-Directional (1)

                            um-Bi-Directional

                                ul-UM-RLC

                                    sn-FieldLength: size10 (1)

                                dl-UM-RLC

                                    sn-FieldLength: size10 (1)

                                    t-Reordering: ms50 (10)

                        logicalChannelIdentity: 4

                        logicalChannelConfig

                            ul-SpecificParameters

                                priority: 13

                                prioritisedBitRate: infinity (7)

                                bucketSizeDuration: ms100 (1)

                                logicalChannelGroup: 2

            mac-MainConfig: explicitValue (0)

                                    ...

            physicalConfigDedicated

                                    ...

 

Following is handoverPreparation message captured at X2 interface. DRB ID is marked in Red and some other IDs are also marked in blue for your reference.

 

EUTRAN X2 Application Protocol (X2AP)

    X2AP-PDU: initiatingMessage (0)

        initiatingMessage

            procedureCode: id-handoverPreparation (0)

            criticality: reject (0)

            value

                HandoverRequest

                    protocolIEs: 6 items

                        Item 0: id-Old-eNB-UE-X2AP-ID

                            ProtocolIE-Field

                                id: id-Old-eNB-UE-X2AP-ID (10)

                                criticality: reject (0)

                                value

                                    UE-X2AP-ID: 2

                        Item 1: id-Cause

                            ...

                        Item 2: id-TargetCell-ID

                            ...

                        Item 3: id-GUMMEI-ID

                            ...

                        Item 4: id-UE-ContextInformation

                            ProtocolIE-Field

                                id: id-UE-ContextInformation (14)

                                criticality: reject (0)

                                value

                                    UE-ContextInformation

                                        mME-UE-S1AP-ID: 123456789

                                        uESecurityCapabilities

                                            ...

                                        aS-SecurityInformation

                                            ...

                                        uEaggregateMaximumBitRate

                                            ...

                                        subscriberProfileIDforRFP: 1

                                        e-RABs-ToBeSetup-List: 1 item

                                            Item 0: id-E-RABs-ToBeSetup-Item

                                                ProtocolIE-Single-Container

                                                    id: id-E-RABs-ToBeSetup-Item (4)

                                                    criticality: ignore (1)

                                                    value

                                                        E-RABs-ToBeSetup-Item

                                                            e-RAB-ID: 5

                                                            e-RAB-Level-QoS-Parameters

                                                                qCI: 9

                                                                allocationAndRetentionPriority

                                                                    ...

                                                            dL-Forwarding: dL-forwardingProposed (0)

                                                            uL-GTPtunnelEndpoint

                                                                ...

                                                                gTP-TEID: 024a4023

                                        rRC-Context: ...

                                        HandoverPreparationInformation

                                            criticalExtensions: c1 (0)

                                                c1: handoverPreparationInformation-r8 (0)

                                                    handoverPreparationInformation-r8

                                                        ue-RadioAccessCapabilityInfo: 1 item

                                                            Item 0

                                                                UE-CapabilityRAT-Container

                                                                    ...

                                                                       

                                                        as-Config

                                                            ...

                                                            sourceRadioResourceConfig

                                                                srb-ToAddModList: 2 items

                                                                    Item 0

                                                                        SRB-ToAddMod

                                                                            srb-Identity: 1

                                                                            ...

                                                                    Item 1

                                                                        SRB-ToAddMod

                                                                            srb-Identity: 2

                                                                            ...

                                                                drb-ToAddModList: 1 item

                                                                    Item 0

                                                                        DRB-ToAddMod

                                                                            eps-BearerIdentity: 5

                                                                            drb-Identity: 2

                                                                            pdcp-Config

                                                                                ...

                                                                            rlc-Config: am (0)

                                                                                ...

                                                                            logicalChannelIdentity: 3

                                                                            logicalChannelConfig

                                                                                ...

                                                                mac-MainConfig: explicitValue (0)

                                                                    ...

                                                                sps-Config

                                                                    ...

                                                                physicalConfigDedicated

                                                                    ...

                        Item 5: id-UE-HistoryInformation

                            ...

 

 

E-RAB ID

 

 

S1 Application Protocol

    S1AP-PDU: initiatingMessage (0)

        initiatingMessage

            procedureCode: id-InitialContextSetup (9)

            criticality: reject (0)

            value

                InitialContextSetupRequest

                    protocolIEs: 8 items

                        Item 0: id-MME-UE-S1AP-ID

                            ProtocolIE-Field

                                id: id-MME-UE-S1AP-ID (0)

                                criticality: reject (0)

                                value

                                    MME-UE-S1AP-ID: 285212685

                        Item 1: id-eNB-UE-S1AP-ID

                            ProtocolIE-Field

                                id: id-eNB-UE-S1AP-ID (8)

                                criticality: reject (0)

                                value

                                    ENB-UE-S1AP-ID: 3

                        Item 2: id-uEaggregateMaximumBitrate

                        Item 3: id-E-RABToBeSetupListCtxtSUReq

                            ProtocolIE-Field

                                id: id-E-RABToBeSetupListCtxtSUReq (24)

                                criticality: reject (0)

                                value

                                    E-RABToBeSetupListCtxtSUReq: 1 item

                                        Item 0: id-E-RABToBeSetupItemCtxtSUReq

                                            ProtocolIE-SingleContainer

                                                id: id-E-RABToBeSetupItemCtxtSUReq (52)

                                                criticality: reject (0)

                                                value

                                                    E-RABToBeSetupItemCtxtSUReq

                                                        e-RAB-ID: 5

                                                        e-RABlevelQoSParameters

                                                            qCI: 9

                                                            allocationRetentionPriority

                                                                ...

                                                      transportLayerAddress: 12345678 ...

                                                        gTP-TEID: 12345678

                                                        ...

                                                            EPS mobile identity - GUTI

                                                                Element ID: 0x50

                                                                Length: 11

                                                                .... 0... = odd/even indic: 0

                                                                .... .110 = Type of identity: GUTI

                                                                Mobile Country Code (MCC): 001

                                                                Mobile Network Code (MNC): 01

                                                                MME Group ID: 12345

                                                                MME Code: 12

                                                                M-TMSI: 0x12345678

                                                            ....

                        Item 4: ...

 

 

 

EUTRAN X2 Application Protocol (X2AP)

    X2AP-PDU: initiatingMessage (0)

        initiatingMessage

            procedureCode: id-handoverPreparation (0)

            criticality: reject (0)

            value

                HandoverRequest

                    protocolIEs: 6 items

                        Item 0: id-Old-eNB-UE-X2AP-ID

                            ProtocolIE-Field

                                id: id-Old-eNB-UE-X2AP-ID (10)

                                criticality: reject (0)

                                value

                                    UE-X2AP-ID: 2

                        Item 1: id-Cause

                            ProtocolIE-Field

                                id: id-Cause (5)

                                criticality: ignore (1)

                                value

                                    Cause: radioNetwork (0)

                                        radioNetwork: handover-desirable-for-radio-reasons (0)

                        Item 2: id-TargetCell-ID

                            ProtocolIE-Field

                                id: id-TargetCell-ID (11)

                                criticality: reject (0)

                                value

                                    ECGI

                                        pLMN-Identity: 123456

                                        Mobile Country Code (MCC): 001

                                        Mobile Network Code (MNC): 01

                                        eUTRANcellIdentifier: 12345678

                        Item 3: id-GUMMEI-ID

                            ProtocolIE-Field

                                id: id-GUMMEI-ID (23)

                                criticality: reject (0)

                                value

                                    GUMMEI

                                        gU-Group-ID

                                            pLMN-Identity: 123456

                                            Mobile Country Code (MCC): 001

                                            Mobile Network Code (MNC): 01

                                            mME-Group-ID: 1234

                                        mME-Code: 21

                        Item 4: id-UE-ContextInformation

                            ProtocolIE-Field

                                id: id-UE-ContextInformation (14)

                                criticality: reject (0)

                                value

                                    UE-ContextInformation

                                        ...

                                        e-RABs-ToBeSetup-List: 1 item

                                            Item 0: id-E-RABs-ToBeSetup-Item

                                                ProtocolIE-Single-Container

                                                    id: id-E-RABs-ToBeSetup-Item (4)

                                                    criticality: ignore (1)

                                                    value

                                                        E-RABs-ToBeSetup-Item

                                                            e-RAB-ID: 5

                                                            e-RAB-Level-QoS-Parameters

                                                            ...

                                                            uL-GTPtunnelEndpoint

                                                                ...

                                                                transportLayerAddress: xxxxxxxx

                                                                    transportLayerAddress(IPv4):

                                                                                   xxx.xxx.xxx.xxx

                                                                gTP-TEID: 12345678

                                        rRC-Context: < RRC HEX >...

                                        HandoverPreparationInformation

                                            criticalExtensions: c1 (0)

                                                c1: handoverPreparationInformation-r8 (0)

                                                    handoverPreparationInformation-r8

                                                        ue-RadioAccessCapabilityInfo: 1 item

                                                            Item 0

                                                                UE-CapabilityRAT-Container

                                                                    rat-Type: eutra (0)

                                                                    ueCapabilityRAT-Container:

                                                                                 < Hex String >...

                                                                        

                                                        as-Config

                                                            ...                    

                        Item 5: id-UE-HistoryInformation

                            ProtocolIE-Field

                                id: id-UE-HistoryInformation (15)

                                criticality: ignore (1)

                                value

                                    UE-HistoryInformation: 1 item

                                        Item 0

                                            LastVisitedCell-Item: e-UTRAN-Cell (0)

                                                e-UTRAN-Cell

                                                    global-Cell-ID

                                                        pLMN-Identity: 123456

                                                        Mobile Country Code (MCC): 001

                                                        Mobile Network Code (MNC): 01

                                                        eUTRANcellIdentifier: 12345678

                                                    cellType

                                                        cell-Size: small (1)

                                                    time-UE-StayedInCell: 11

 

 

Followings are some examples of TEID in X2AP messages. I made visible some other types of IDs as well for your reference.

 

EUTRAN X2 Application Protocol (X2AP)

    X2AP-PDU: successfulOutcome (1)

        successfulOutcome

            procedureCode: id-handoverPreparation (0)

            criticality: reject (0)

            value

                HandoverRequestAcknowledge

                    protocolIEs: 4 items

                        Item 0: id-Old-eNB-UE-X2AP-ID

                            ProtocolIE-Field

                                id: id-Old-eNB-UE-X2AP-ID (10)

                                criticality: ignore (1)

                                value

                                    UE-X2AP-ID: 2

                        Item 1: id-New-eNB-UE-X2AP-ID

                            ProtocolIE-Field

                                id: id-New-eNB-UE-X2AP-ID (9)

                                criticality: ignore (1)

                                value

                                    UE-X2AP-ID: 1

                        Item 2: id-E-RABs-Admitted-List

                            ProtocolIE-Field

                                id: id-E-RABs-Admitted-List (1)

                                criticality: ignore (1)

                                value

                                    E-RABs-Admitted-List: 1 item

                                        Item 0: id-E-RABs-Admitted-Item

                                            ProtocolIE-Single-Container

                                                id: id-E-RABs-Admitted-Item (0)

                                                criticality: ignore (1)

                                                value

                                                    E-RABs-Admitted-Item

                                                        e-RAB-ID: 5

                                                        uL-GTP-TunnelEndpoint

                                                            ...0 .... Extension Present Bit: False

                                                            transportLayerAddress: xxxxxxxx

                                                                transportLayerAddress(IPv4):

                                                                                 xxx.xxx.xxx.xxx

                                                            gTP-TEID: 12345678

                                                        dL-GTP-TunnelEndpoint

                                                            ..0. .... Extension Present Bit: False

                                                            transportLayerAddress: xxxxxxxx

                                                                transportLayerAddress(IPv4):

                                                                                 xxx.xxx.xxx.xxx

                                                            gTP-TEID: 12345678

                        Item 3: id-TargeteNBtoSource-eNBTransparentContainer

                            ProtocolIE-Field

                                id: id-TargeteNBtoSource-eNBTransparentContainer (12)

                                criticality: ignore (1)

                                value

                                    TargeteNBtoSource-eNBTransparentContainer: < Hex String ...>

                                    HandoverCommand

                                        criticalExtensions: c1 (0)

                                            c1: handoverCommand-r8 (0)

                                                handoverCommand-r8

                                                    handoverCommandMessage: < Hex String ...>

                                                        DL-DCCH-Message

                                                            message: c1 (0)

                                                                ....