From: "Elwell, John" <[email protected]>
An interesting draft addressing a known problem space. Dan Wing has
already pointed out similarities with draft-wing-sip-e164-rrc (now
expired). I fear the present draft will not work in the presence of
B2BUAs along the path of the INVITE request, since these tend to
change things like call-ID, to-tag and from-tag. Since B2BUAs, and
SBCs in particular, are the main reasons why RFC 4474 will not
work, any solution has to be able to work through these devices.
However... If we change the sequence of operations a bit, so that the
UAS sends a 183 with a Contact carrying a specific header parameter
carrying a crypto-random value, and we get B2BUAs to pass it through
(attaching it to the Contact they use in the 183 they emit on the
other side), then if the UAS does a non-filtered dialog event
SUBSCRIBE, it can check the returned NOTIFY to see if it carries the
Contact header parameter that it created. That's a reasonably good
test that the UAC of the INVITE can be reached via the From value that
the UAS received.
Dale
_______________________________________________
Sip mailing list https://www.ietf.org/mailman/listinfo/sip
This list is for NEW development of the core SIP Protocol
Use [email protected] for questions on current sip
Use [email protected] for new developments on the application of sip
lmpx.com only provides a reader for public news (NNTP) servers. It is not
affiliated with the servers or forums shown here and is not responsible for
the content of articles, which is written by their respective authors.