> Regarding your following comment; > > "The transport type might not be the reason that they > are ignoring the request. And if it is, there may be > a configuration issue." > > Are you trying to say that, irrespective of session is > occurred using any transport, if the session termination > request (or any other mid-session request) is generated > using different transport, then also it shall be > entertained? Is such thing mentioned in any RFC?
No; I'm indicating that requests can fail for a variety of reasons which includes bad configuration. However, yes; using the non preferred transport type may be entertained and is mentioned within the RFCs. RFC 3261 section 18.1.1: "If a request is within 200 bytes of the path MTU, or if it is larger than 1300 bytes and the path MTU is unknown, the request MUST be sent using an RFC 2914 [43] congestion controlled transport protocol, such as TCP. If this causes a change in the transport protocol from the one indicated in the top Via, the value in the top Via MUST be changed." "If an element sends a request over TCP because of these message size constraints, and that request would have otherwise been sent over UDP, if the attempt to establish the connection generates either an ICMP Protocol Not Supported, or results in a TCP reset, the element SHOULD retry the request, using UDP." RFC 3263 section 4.1: "Otherwise, if no transport protocol is specified, but the TARGET is a numeric IP address, the client SHOULD use UDP for a SIP URI, and TCP for a SIPS URI. Similarly, if no transport protocol is specified, and the TARGET is not numeric, but an explicit port is provided, the client SHOULD use UDP for a SIP URI, and TCP for a SIPS URI. This is because UDP is the only mandatory transport in RFC 2543 [6], and thus the only one guaranteed to be interoperable for a SIP URI. It was also specified as the default transport in RFC 2543 when no transport was present in the SIP URI. However, another transport, such as TCP, MAY be used if the guidelines of SIP mandate it for this particular request. That is the case, for example, for requests that exceed the path MTU." _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
