2.2.19 Option Tag extensions

This section follows the product behavior described in endnote <13>.

This protocol defines option tags for use in the Supported header field. The new tags extend the set of option tags defined in [RFC3261] section 19.2.

Ms-Dialog-Route-Set-Update: Option tag for support of the dialog route set recovery extension. Inclusion of this tag in the Supported header field of the request indicates that the user agent can perform dialog route set recovery, as described in section 3.7.

Ms-Safe-Transfer: Option tag for support of call transfer via SIP REFER request. Inclusion of this tag in the Supported header field of the request indicates that the user agent can copy parameters from the Refer-To header field URI of the REFER request to the INVITE request, as described in section 3.14.