Michael & all, Thanks for your replies. I do have RFC 3891 and 3261. The summary of header parmeter encoding is helpful.
What I'm really looking for is where the UAC/UAS behavior is defined. Somehow, multiple people decided that they should look for this field in the refer-to header of a REFER request and then put then info in the INVITE prompted by the REFER. Now, I cant believe that was coincidence!! Is it documented somewhere or just abstracted from examples like the one in RFC3515 (Refer) and the sipping-service-examples draft? Thanks, Jack -----Original Message----- From: Michael Procter [mailto:[EMAIL PROTECTED] Sent: Thursday, October 05, 2006 2:15 AM To: Jack W. Lix; [email protected] Subject: RE: [Sip-implementors] Replaces tag Jack W. Lix wrote: > > RFC 3515 (Refer) gives the following example in section 2.1 > Refer-To: <sip:[EMAIL PROTECTED] > to-tag%3D12345%3Bfrom-tag%3D5FFE-3994> > > Where is the use of Replaces as a tag defined? The replaces RFC doesnt > mention it or give an example like this. Encoding a header field in a URI is permitted by RFC3261. A few extracts from section 25.1: SIP-URI = "sip:" [ userinfo ] hostport uri-parameters [ headers ] headers = "?" header *( "&" header ) header = hname "=" hvalue hname = 1*( hnv-unreserved / unreserved / escaped ) hvalue = *( hnv-unreserved / unreserved / escaped ) hnv-unreserved = "[" / "]" / "/" / "?" / ":" / "+" / "$" And from section 19.1: Headers: Header fields to be included in a request constructed from the URI. Headers fields in the SIP request can be specified with the "?" mechanism within a URI. The header names and values are encoded in ampersand separated hname = hvalue pairs. The special hname "body" indicates that the associated hvalue is the message-body of the SIP request. There are more details in 19.1.5, including some warnings about dangerous headers which should not be honoured. Regards, Michael Procter _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
