Section: 20.3.4 MBMS session termination (MBMS GW initiated)
Content: Figure 20.3.4.1: MBMS session termination 1. In exceptional cases (e.g. resource pre-emption or timeout of the MBMS session), the MBMS GW may send an STR command to the BM-SC to initiate the termination of the Diameter session related to an MBMS bearer service. If a bearer plane had been established over SGi-mb for this MBMS bearer service, the bearer plane is released. If the MBMS GW detects the SGi-mb path failure as specified in subclause 20.3.2.1 of 3GPP TS 23.007[ Restoration procedures ]  [104], the MBMS GW shall set the Termination-Cause to "DIAMETER_LINK_BROKEN" (see IETF RFC 6733 [111]) and shall include the Diagnostic-Info AVP set to "User Plane Failure" if it tears down the MBMS session as a result of detecting an SGi-mb path failure. 2. The BM-SC removes the Diameter session and confirms the operation by sending an STA message to the MBMS GW.