> UAS receives an INVITE request withh invalid Via Header, > while parsing we found that syntax of Via is wrong so > UAS decided to send 4xx response & not concentrated on > rest of header values.
Sometimes a request is too malformed to bother sending a 400 response. The following are some of the mandatory headers which would cause a 400 if they were missing: Via, To, From, Call-ID, and CSeq. However if you sent the 400 response, it would also be malformed and might not be able to match the malformed request anyway. Thus you can act "Ideally" per RFC 4475 section 3.3.1 and send a 400 response; or you can act non "Ideally" and ignore it. The same applies when the mentioned headers are too malformed to adequately build a 400 response. > Is that mandatory to have Via header in 4xx response ? Yes. > if yes what should be the value of the address and > branch parameter in Via header? The values received with parameters such as received added if needed. > can i use the value of UAS in place of Via header's address > and branch parameter? No. _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
