Re: [Sip] [Sip-implementors] From Tag

["Brett Tate" <brett at broadsoft.com>]

> Why the From-Tag is required?

Per rfc3261, the answer is that the tags and call-id identify the
dialog.

The other answer is that prior to such a requirement, requests in the
opposite direction over the dialog occasionally caused To tag to be
added because the receive was unaware that the dialog was already formed
without the tag.  Similarly a re-INVITE to audit would occasionally
caused the call to be re-established because the receiver (who didn't
add the From tag) did not notice the distinction between INVITE and
re-INVITE.
_______________________________________________
Sip mailing list  https://www.ietf.org/mailman/listinfo/sip
This list is for NEW development of the core SIP Protocol
Use sip-implementors at cs.columbia.edu for questions on current sip
Use sipping at ietf.org for new developments on the application of sip