The PCRF sends an ASR message to the PCEF to stop the service of a specified Session-Id. The Command-Code is set to 274, and the R bit in the flag field is set.
<ASR> ::= < Diameter Header: 274, REQ, PXY > < Session-Id > { Origin-Host } { Origin-Realm } { Destination-Realm } { Destination-Host } { Auth-Application-Id } [ User-Name ] [ Origin-State-Id ] * [ Proxy-Info ] * [ Route-Record ] * [ AVP ]
Section 8.5.1 in RFC 3588