Dedicated Bearer Setup – Request Accepted Partially Call Flow

This section describes the Dedicated Bearer set up call flow. In this procedure, the MME sends the Create Bearer Response with the GTP cause as Request Accepted Partially.

Prerequisite: Create Bearer Procedure with two bearer contexts.

Dedicated Bearer Setup – Request Accepted Partially Call Flow
Dedicated Bearer Setup – Request Accepted Partially Call Flow Description

Step

Description

1

The PGW sends the S5 Create Bearer Request with multiple bearer contexts to the S5-GTPC-EP pod.

2

The S5-GTPC-EP pod forwards the S5 Create Bearer Request to the SGW-SVC pod.

3

The SGW-SVC pod receives the S5 Create Bearer request and performs the following:

  • Creates a new transaction

  • Performs GTP validations

  • Triggers the Sx Modification Request to allocate SGW Ingress and SGW Egress TEIDs to the PFCP-EP pod.

4

The PFCP-EP pod forwards the Sx Modification Request to the UP.

5

The UP sends the Sx Modification Response to the PFCP-EP pod.

6

The PFCP-EP pod forwards the Sx Modification Response to the SGW-SVC pod.

7

The SGW-SVC receives the Sx Modification Response and performs the following:

  • Validates the received SGW Ingress and SGW Egress TEIDs

  • Triggers an S11 Create Bearer Request with the SGW Ingress TEID to the S11-GTPC-EP pod

8

The S11-GTPC-EP pod forwards the S11 Create Bearer Request to the MME.

9

The S11-GTPC-EP receives the S11 Create Bearer Response from the MME, with the Message Level GTP cause as Request Accepted Partially:

  • For some Bearer Contexts, GTP cause is Request Accepted
  • For some Bearer Contexts, GTP cause is Request Rejected

10

The S11-GTPC-EP pod forwards the S11 Create Bearer Response to the SGW-SVC pod.

11

The SGW-SVC pod receives the S11 Create Bearer response and performs the following:

  • GTP validations

  • For successful bearers: Triggers the Sx Modification Request to the PFCP-EP pod for updating SGW Ingress and SGW Egress PDR/FAR with the MME and the PGW GTPU-TEID

  • For failed bearers: Removes the traffic endpoints

12

The PFCP-EP pod forwards the Sx Modification Request to the UP.

13

The UP sends the Sx Modification Response to the PFCP-EP pod.

14

The PFCP-EP pod forwards the Sx Modification Response to the SGW-SVC pod.

15, 16

The SGW-SVC pod receives the Sx Modification Response and performs the following:

  • Ends the transaction/procedure

  • Updates the CDL

  • For successful bearers: Sends the S5 Create Bearer Response with SGW Egress TEIDs with matching PGW GTPU TEIDs.

  • For failed bearers: Sends the bearer contexts as is with the message level cause as Partially Accepted.