Hi all! RFC 3261 explicitly allows the having multiple contacts in a single header.
> 7.3: ... Specifically, any SIP header whose grammar is of the form > > header = "header-name" HCOLON header-value *(COMMA header-value) > > allows for combining header fields of the same name into a comma- > separated list. The Contact header field allows a comma-separated > list unless the header field value is "*". Further RFC 3261 specifies that single and multiple header files have the same semantic: 7.3.1 ... > Multiple header field rows with the same field-name MAY be present in > a message if and only if the entire field-value for that header field > is defined as a comma-separated list (that is, if follows the grammar > defined in Section 7.3). It MUST be possible to combine the multiple > header field rows into one "field-name: field-value" pair, without > changing the semantics of the message, by appending each subsequent > field-value to the first, each separated by a comma. Ok, thus: Contact: <sip:1.1.1.1> Contact: <sip:2.2.2.2> can be written as: Contact: <sip:1.1.1.1>, <sip:2.2.2.2> But what about: Contact: <sip:1.1.1.1>;expires=111 Contact: <sip:2.2.2.2>;expires=222 This can not be written in a single header without changing semantic. Further is this allowed? Contact: <sip:1.1.1.1>, <sip:2.2.2.2>;expires=111 Contact: <sip:3.3.3.3>, <sip:4.4.4.4>;expires=222 What about: Contact: <sip:1.1.1.1> Contact: <sip:2.2.2.2>;expires=222 This can be rewritten as Contact: <sip:1.1.1.1>, <sip:2.2.2.2>;expires=222 Does this imply that a missing expires header means that the expires is equivalent to the expires of the next Contact header with expires parameter? How should we deal with such scenarios? thanks klaus _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
