Related specifications
draft-ietf-sipping-service-examples-12.txt, Session Initiation Protocol Service Examples, available at http://www.ietf.org/
RFC 3515, The Session Initiation Protocol (SIP) Refer Method, available at http://www.ietf.org/
RFC 3891, The Session Initiation Protocol (SIP) "Replaces" Header, available at http://www.ietf.org/
RFC 3892, The Session Initiation Protocol (SIP) Referred-By Mechanism, available at http://www.ietf.org/
ETSI TS 183 029 PSTN/ISDN simulation services: Explicit Communication Transfer (ECT); Protocol specification V1.1.1, available at http://www.etsi.org
Implementation notes
Support is provided for:
Receiving Attended call transfer. (Section 2.5, draft-ietf-sipping-service-examples-12.txt.)
Receiving unattended call transfer from remote party. (Section 2.4, draft-ietf-sipping-service-examples-12.txt.)
Rejected transfer by sending response 503, ‘Service Unavailable’ to REFER.
Failed transfer by sending NOTIFY with response 503 ‘Service Unavailable’. No other failing NOTIFY responses are sent.
Support is not provided for:
REFER arriving in a new dialog.
Initiating Attended call transfer. (Section 2.5, draft-ietf-sipping-service-examples-12.txt.)
Initiating unattended call transfer. (Section 2.4, draft-ietf-sipping-service-examples-12.txt.)
Multiple REFER requests in a dialog. (Section 2.4.6, RFC 3515.)