> 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-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
