Folks, I've have committed new version of RTP proxy and nathelper into the SER's cvs. One of the main changes in the new version is support for so-called "bridge mode" in nathelper, which allows to create application-level SIP gateways (e.g. ALG) on NAT box, to allow NATed clients to make calls into WAN without any problems (or on IPv4/IPv6 gateway to allow IPv4<->IPv6 calls). The mode is activated by supplying RTP proxy with two listen addresses, for example: rtpproxy -l 1.1.1.1/2.2.2.2, in this case it means that 1.1.1.1 is "external" address (WAN), while "2.2.2.2" is "internal" one (LAN). Of course terms "internal" and "external" aren't magic, they are used for convinience to avoid using something like "address1" and "address2". For IPv4<->IPv6 command line will be: rtpproxy -l <IPv4> -6 /<IPv6>, or rtpproxy -l /<IPv4> -6 <IPv6>, correspondingly in the first case IPv4 will be considered "external", while IPv6 "internal", while in the second one vice versa. Then, you have to configure ser properly, exact config is left as a excersise to the reader, but the main principles are the following: 1. For proper bridging you have to enable loose routing, so that all SIP signalling always goes through proxy (remember, UAs on LAN can't talk to UAs on WAN directly). 2. In main route add something like the following to enable RTP bridging: if (<some check that message is received from LAN>) { force_rtp_proxy("i"); } else { force_rtp_proxy(); }; This is no need to do such "black" magick in reply_route(), use as usual: onreply_route[1] { ... if (status=~"183" || status=~"200") force_rtp_proxy(); ... } The code is only lightly tested, so that there might be bugs. Please report them to me. Please also note that IPv6 support is imcomplete since nathelper can't yet extract and rewrite IPv6 addresses and RTP proxy can't yet pre-load IPv6 addresses when creating a session. However, main infrastructure is in place, so that it can be coded in quite easily (patches or sponsorship ;-) as usually are welcome). -Maxim -------- Original Message -------- Subject: [Serdev] CVS:commitlog: sip_router/modules/nathelper nathelper.c Date: Mon, 9 Feb 2004 16:05:03 +0100 From: Maxim Sobolev &lt;sobomax(a)portaone.com&gt; To: serdev(a)lists.iptel.org sobomax 2004/02/09 16:05:03 CET SER CVS Repository Modified files: modules/nathelper nathelper.c Log: o force_rtp_proxy now accepts option argument, which consists of string of chars, each of them turns "on" some feature, currently supported ones are: `a' - flags that UA from which message is received doesn't support symmetric RTP; `l' - force "lookup", that is, only rewrite SDP when corresponding session is already exists in the RTP proxy. Only makes sense for SIP requests, replies are always processed in "lookup" mode; 'i' - flags that message is received from UA in the LAN. Only makes sense when RTP proxy is rinning in the bridge mode. NOTE: proper support for those flags requires very last version of RTP proxy software at this time only available from cvs. o force_rtp_proxy can now be invoked without any argumens, as previously, with one argument - in this case argument is treated as option string and with two arguments, in which case 1st argument is option string and the 2nd one is IP address which have to be inserted into SDP (IP address on which RTP proxy listens). Revision Changes Path 1.40 +130 -50 sip_router/modules/nathelper/nathelper.c http://cvs.berlios.de/cgi-bin/viewcvs.cgi/ser/sip_router/modules/nathelper/…