[OpenSER-Users] Why OpenSer sends a "NOTIFY" when un-SUBSCRIBE for a contact?

Hi, if I send a un-SUBSCRIBE: ------------------------------------------------------------------ SUBSCRIBE sip:OPENSER_IP SIP/2.0 To: <sip:piru@domain.org>;tag=10.30692.1202986670.2 From: <sip:angel@domain.org>;tag=utxpu Accept: application/pidf+xml Event: presence Expires: 0 ------------------------------------------------------------------ then OpenSer replies with a 202 OK: ------------------------------------------------------------------ SIP/2.0 202 OK Expires: 0 ------------------------------------------------------------------ and later OpenSer sends me a NOTIFY: ------------------------------------------------------------------ NOTIFY sip:angel_aliax_net@212.121.235.18:5060 SIP/2.0 To: sip:angel@domain.org;tag=utxpu From: sip:piru@domain.org;tag=10.30692.1202986670.2 Event: presence Subscription-State: terminated;reason=timeout Content-Type: application/pidf+xml <?xml version="1.0" encoding="UTF-8"?> <presence xmlns="urn:ietf:params:xml:ns:pidf" entity="sip:piru@domain.org"> <tuple id="mzlben"> <status> <basic>open</basic> </status> </tuple> </presence> ------------------------------------------------------------------ My question is: why OpenSer sends the pidf+xml body in the NOTIFY? it's obvious that the user has no interest in the presence status of that contact. Maybe it's RFC mandatory? -- Iñaki Baz Castillo ibc(a)in.ilimit.es