2.2.1.5 Supported Header Field Extensions

This protocol extends the Supported header field for the REGISTER request with the following new option tags.

adhoclist: The UAC SHOULD add this option tag in the Supported header field in the REGISTER request if the UAC supports batched subscribe requests, as specified in [MS-SIP] section 3.3.4.1.

com.microsoft.msrtc.presence: The UAC SHOULD add this option tag in the Supported header field in the REGISTER request if the UAC supports the Presence Protocol, as specified in [MS-SIP] section 3.2.4.1.

msrtc-event-categories: The UAC SHOULD add this option tag in the Supported header field in the REGISTER request if the UAC supports the Presence Protocol, as specified in [MS-PRES] section 2.2.2.4.1.

gruu-10: Used by the UAC for requesting the Globally Routable User Agent URI (GRUU) specified in [IETFDRAFT-OUGRUAUSIP-10] section 6. The UAC SHOULD add this option tag in the Supported header field in the REGISTER request.

ms-forking: This tag is deprecated and SHOULD NOT be sent in requests.

ms-userservices-state-notification: The UAC SHOULD<4> add this option tag in the Supported header field in the REGISTER request if the UAC supports survivable mode registration, which is registration without the availability of the service that handles the Presence Protocol specified in [MS-PRES] section 1.

ms-cluster-failover: The UAC SHOULD<5> add this option tag to the Supported header field in the REGISTER request if the UAC supports serial processing of contact headers in decreasing q-value order, as specified in [RFC3261] section 10.2.

The ABNF, as defined in [RFC5234], syntax listing specified in [RFC3261] section 25.1 is extended as follows:

 Supported  =  ( "Supported" / "k" ) HCOLON ["adhoclist" / "com.microsoft.msrtc.presence" / "msrtc-event-categories" / "gruu-10" / "ms-userservices-state-notification" / "ms-cluster-failover" / option-tag *(COMMA option-tag)]