Thanks, Iñaki. But It is not what I really need. I need to send to an UAS a SIP Request, like OPTIONS, and tell it to send the reply to a different transport address (IP Addr + Port) than the source address of the request.

This is, basically, in order to perform NAT discovering and typing from the server.

El Monday 07 April 2008 23:52:08 Victor Cartes escribió: send source That is not possible at all, a UAS decides where to send the reply based on the "received" and "rport" values (if UAC indicated it) that the UAS transport layer has set when receiving the request. the Is not enought to analize NAT during clients REGISTER? why you need it? Regards. -- Iñaki Baz Castillo ibc(a)in.ilimit.es _______________________________________________ Users mailing list Users(a)lists.openser.org http://lists.openser.org/cgi-bin/mailman/listinfo/users

El Tuesday 08 April 2008 14:14:08 Victor Cartes escribió: I the Ok, but as I said it's not possible in SIP to request that a reply goes to a different address:port than the indicated in received:rport of Via header. It's the UAS who decides it based on the request Via and source ip:port from where it has received the request. You'll need to think in other way :( -- Iñaki Baz Castillo ibc(a)in.ilimit.es _______________________________________________ Users mailing list Users(a)lists.openser.org http://lists.openser.org/cgi-bin/mailman/listinfo/users

El Martes, 8 de Abril de 2008, Victor Cartes escribió: transport that when I You are minunderstanding the behaviour of "received" and "rport". "received" is not (and cannot be) set by the UAC, but just by the UAS. This is: http://tools.ietf.org/html/rfc3261#section-18.2.1 --------------------------------------------------- When the server transport receives a request over any transport, it MUST examine the value of the "sent-by" parameter in the top Via header field value. If the host portion of the "sent-by" parameter contains a domain name, or if it contains an IP address that differs from the packet source address, the server MUST add a "received" parameter to that Via header field value. This parameter MUST contain the source address from which the packet was received. This is to assist the server transport layer in sending the response, since it must be sent to the source IP address from which the request came. Consider a request received by the server transport which looks like, in part: INVITE sip:bob@Biloxi.com SIP/2.0 Via: SIP/2.0/UDP bobspc.biloxi.com:5060 The request is received with a source IP address of 192.0.2.4. Before passing the request up, the transport adds a "received" parameter, so that the request would look like, in part: INVITE sip:bob@Biloxi.com SIP/2.0 Via: SIP/2.0/UDP bobspc.biloxi.com:5060;received=192.0.2.4 --------------------------------------------------- "rport" is the same as "reveiced" but for the IP and it's defined in http://tools.ietf.org/html/rfc3581. But there is a BIG difference: The UAC MUST add "rport" (with no value) to its Via header to indicate the UAS that UAC supports RFC 3581. So: 1) A UAC adds "rport" (with no value) to Via of the request and sends it to UAS. 2) UAS recives the request and compares the IP in the sent-by field of Via header with the source IP of the received request. If both are different then UAS transport layer adds "received=SOURCE_IP" to the Via header 3) Since the received Via includes "rport" it means that the UAC supports RFC 3851. Then UAS transport layer compares port indicated in sent-by field with the real source port of the received request. If they are different then UAS transport layer adds the value of real source port as the value of "rport" parameter in Via header. 4) Now UAS can reply, passes the request to transaction layer or UAS core. When it generates a response this will go to "received:rport". If "Via" didn't include "rport" (with no value) then UAS MUSN'T add "rport=source_port" to Via header and will send replies to "received":"sent-by-port" (obvisouly this will fail in NAT scenarios). You said: transport that but you are wrong, a UAC CAN NEVER add "received" to Via, it makes no sense at all since UAC cannot know which will be the real source IP the UAS will receive the request from (there can be SIP proxies, NAT routers...). A UAS receiving a request with "received" in Via MUST ignore it completely (or maybe reject the request as malformed). Hope it helps you :) -- Iñaki Baz Castillo _______________________________________________ Users mailing list Users(a)lists.openser.org http://lists.openser.org/cgi-bin/mailman/listinfo/users

"rport" is the same as "reveiced" but for the IP