Re: [OpenSER-Users] NAT problem in bridging mode

Try to use flag 'w' when you use force_rtp_proxy(). http://www.openser.org/docs/modules/1.3.x/nathelper.html#AEN316 Regards, Ovidiu Sas On Wed, May 21, 2008 at 8:23 AM, Christian Koch &lt;chri.koch.vier(a)googlemail.com&gt; wrote: > Just in case anybody is facing the same problem: I found the solution > for this configuration. rtpproxy handles the bridging mode in a way > which doesn't fit my configuration. It assumes UAC1 is not behind a NAT. > So you have to remove the following line from the rtpproxy code and > recompile: > > asymmetric = (bmode != 0) ? 1 : 0; > > See also: http://lists.iptel.org/pipermail/serusers/2004-June/009305.html > > I will ask on the rtpproxy mailing list for the reasons for this > behaviour, as I think it may be a bug. > > > > Christian Koch schrieb: > >> Hi, >> >> I have a problem with openser and rtpproxy. I'm trying to use them as >> a gateway between the public internet and a LAN. Clients in the >> internet may be natted, so I'm using nathelper. Calls are only made >> from LAN to outside or vice versa, but not from LAN to LAN or from >> outside to outside. The following should illustrate my configuation: >> ----- ------------------ >> UAC1 --- | NAT | ------------- | OpenSER/rtpproxy | ----------------UAC2 >> ----- ------------------ | >> | | | | >> dynamic public IP 2.3.4.5 192.168.103.121 >> 192.168.103.189 >> (e.g. 1.2.3.4) >> UAC1 and UAC2 are both registered at OpenSER. Now >> I'm making a call from UAC1 to UAC2. SIP messages are passed just >> fine, but the RTP traffic from UAC2 to UAC1 is dropped at the NAT. I >> used tcpdump on the OpenSER/rtpproxy machine to figure out what >> happens to RTP and it shows the following (ports and IPs are just >> examples): >> >> >> stream1: 1.2.3.4:10000 -> 2.3.4.5:35000 ->RTP is forwarded by >> rtpproxy-> 192.168.103.121:35000 -> 192.168.103.189:11000 >> stream2: 1.2.3.4:20000 <- 2.3.4.5:35000 <-RTP is forwarded by >> rtpproxy<- 192.168.103.121:35000 <- 192.168.103.189:11000 >> >> Port 20000 in stream2 is the RTP-port used internally by UAC1 behind >> the NAT (this port is found in the INVITE from UAC1 to OpenSER). I >> understand, that rtpproxy sends the first packets to port 20000. But, >> after receiving some packets from port 10000, shouldn't it change the >> destination port to 20000 so they can pass the NAT? >> rtpproxy is started like this: "./rtpproxy -l 192.168.103.121/2.3.4.5 >> -f ". >> It produces the following output: >> >> [root@192 rtpproxy]# /usr/local/bin/rtpproxy -l >> 192.168.103.121/2.3.4.5 -f >> rtpproxy started, pid 22125 >> received command "UIE >> 9D740CB7-18A4-40B2-A96D-13FC3C5B27D3(a)192.168.103.189 192.168.103.189 >> 49156 207860870326595;1" >> new session 9D740CB7-18A4-40B2-A96D-13FC3C5B27D3(a)192.168.103.189, >> tag 207860870326595;1 requested, type strong >> new session on a port 35000 created, tag 207860870326595;1 >> pre-filling caller's address with 192.168.103.189:49156 >> sending reply "35000 2.3.4.5 >> " >> received command "L >> 9D740CB7-18A4-40B2-A96D-13FC3C5B27D3(a)192.168.103.189 1.2.3.4 49154 >> 207860870326595;1 5364140283;1" >> lookup on ports 35000/35000, session timer restarted >> pre-filling callee's address with 1.2.3.4:49154 >> sending reply "35000 192.168.103.121 >> >> In my openser.cfg I'm not really checking wheter a client is really >> natted, but I think it shouldn't be a problem to assume, that all >> clients are behind a NAT? I attached the openser.cfg to this mail >> (real public IP is changed to 2.3.4.5). >> Do you have any ideas how to fix this problem? Any help would be >> greatly appreciated! >> >> Thanks, >> Christian >> > _______________________________________________ > Users mailing list > Users(a)lists.openser.org > http://lists.openser.org/cgi-bin/mailman/listinfo/users > >