For IES and VPRN services, only down MEP is supported on Ethernet SAPs and spoke SDP bindings.
When a down MEP detects a fault and fault propagation is enabled for the MEP, CFM communicates the fault to the SMGR. The SMGR marks the SAP/SDP binding as operationally down. CFM traffic can still be transmitted to or received from the SAP and SDP-binding to ensure when the fault is cleared and the SAP goes back to normal operational state.
Because the SAP and SDP-binding goes down, it is not usable to upper applications. In this case, the IP interface on the SAP and SDP-binding go down. The prefix is withdrawn from routing updates to the remote PEs. The same applies to subscriber group interface SAPs on the 7450 ESS and 7750 SR.
When the IP interface is administratively shutdown, the SMGR notifies the down MEP and a CFM fault notification is generated to the CPE through interface status TLV or suspension of CCM based on local configuration.