17D Restoration of data in the BM-SC

23.0073GPPRelease 18Restoration proceduresTS

17D.1 Restart of the BM-SC

When a BM-SC fails, all its MBMS Bearer contexts affected by the failure become invalid and will be deleted.

After a BM-SC restart, all the MBMS Bearer contexts stored in the BM-SC and affected by the restart become invalid and will be deleted. All the SGmb Diameter sessions affected by the restart are also lost in the BM-SC. If Group Communication Service (GCS) is supported, the BM-SC also loses the knowledge of the TMGIs it had allocated to the Group Communication Service Application Server(s) (GCS AS) before restarting.

When the MBMS GW detects the restart of a BM-SC, it shall behave as described in clause 17A.2.3.

When the GCS AS detects the restart of a BM-SC, it shall behave as described in clause 17E.1. The restoration of MBMS services by content providers other than GCS AS after a BM-SC failure or restart is out of scope of 3GPP.

NOTE: The reference point from content providers other than GCS AS to the BM-SC is not standardised by 3GPP.

17D.2 Restart of the GCS AS

In deployments without a Diameter Agent between the GCS AS and the BM-SC, the BM-SC shall detect a restart in the GCS AS using either:

– the Diameter Origin-State-Id AVP as specified in the Diameter Base Protocol. To enable fast detection of restart, the Diameter Origin-State-Id AVP shall be included (at least) in Capabilities-Exchange-Request and Capabilities-Exchange-Answer commands; or

– the Diameter Restart-Counter AVP as specified in the MBMS Heartbeat procedure (see clause 29), if this procedure is supported.

In deployments with a Diameter Agent between the GCS AS and the BM-SC, the BM-SC shall detect a restart in the GCS AS using the Diameter Restart-Counter AVP as specified in the MBMS Heartbeat procedure (see clause 29).

NOTE: The intermediate Diameter Agent can remove or update the Diameter Origin-State-Id AVP, e.g. if it needs to modify the Origin-Host-ID. Thus the Diameter Origin-State-Id AVP, if received by the BM-SC or GCS AS, does not reflect the state of the remote MBMS peer but the state of the Diameter Agent.

When the BM-SC detects a restart of the GCS AS, the BM-SC shall deallocate (locally) all the TMGIs that had been assigned to the restarted GCS AS and the BM-SC shall stop all the related MBMS bearers to free the corresponding resources in E-UTRAN.