Hi,
I have question on the RFC related to the "From" field. In the "From" field there is a requirement to define a "tag" parameter (MUST). I am unable to create a
scenario wherein this would be required from the UAC perspective.
Also, could anyone indicate as to why the retransmission of INVITE responses
are done for a TCP connectivity. TCP itself is a reliable transport. Even if we have intermediate proxies or other carriers I am assuming that when they implement UDP on the way, they would have retransmission logic built in. The other thing is if a SIP message indicates that the transport is TCP and if any proxy on the way does not support this transport there is supposed to be an error code returned back. Is this correct?
Would appreciate if anyone could throw some light on this or even if possible any web site which indicates a link to this kind of info.
Thanks,
Sriram
