[SR-Users] Selective rport behaviour

Hi, In some scenarios, it happens that a request is received with the following characteristics: IP xxx.xxx.xxx.xxx:14000 -> server:5060 Via: SIP/2.0/xxx.xxx.xxx.xxx:5060;branch=9hG4bKblah;rport Normally, we just force_rport() on all incoming requests so that we reply to the real source port of the request, since most endpoints on this installation are NAT'd. However, occasionally we run into a scenario where an ALG or misconfigured client incorrectly inserts an rport attribute into its topmost Via, and really expects to receive a response at the address/port indicated in the Via (i.e. 5060). Does Kamailio offer a means of dealing with these on a selective basis? Would refraining from calling force_rport() be enough? Or would it be necessary to set reply_to_via=1 as well, thus breaking symmetrical behaviour for the vast majority of the NAT'd endpoints? In other words, I'm not 100% clear on the following: 1) What impact does force_rport() have if an 'rport' attribute is sent by the client? In this case, there should be nothing to "force"; I assume that if the 'rport' attribute is placed by the client, then the proxy will return replies to the source port of the request even if force_rport() is not called, because that's the RFC 3581-compatible thing to do. Right? 2) Does reply_to_via=1 override the behaviour hypothesised in #1? 3) Does reply_to_via=1 override force_rport()? Thanks! -- Alex -- Alex Balashov | Principal | Evariste Systems LLC Tel: +1-706-510-6800 (direct) / +1-800-250-5920 (toll-free) Web: http://www.evaristesys.com/, http://www.csrpswitch.com/