Hi,
my plan is to give the possibility for multiple VoIP users within the same LAN to call each other using OpenSER as the SIP server. I found that if there is a NATed LAN, two different VoIP users inside the NATed LAN cannot talk to each other properly, because IP parts of the RTP packets are of the form of the local network and it is not acceptable by the VoIP software which is prepared for the IP of the router instead. (I hope I understand clearly what is going on here.)
As a workaround, I found a suggestion in the internet: using rtpproxy with OpenSER. As I can understand, all RTP packets are sent to the rtpproxy process via OpenSER (nathelper module). rtpproxy will behave as a bridge between the two NATed VoIP clients lying in the same LAN. Both clients will initiate their RTP/UDP traffic on their own side and answers will come from the rtpproxy process just for the same UDP pipe. Using this method the clients do not need to allow incoming UDP traffic, only outgoing traffic should be enabled (which is usually allowed by default in most LANs).
Here comes my question. I successfully set up OpenSER (version 1.1.x, but I will migrate to 1.2.x soon). I think I also successfully set up rtpproxy, but it seems that there is no real traffic between OpenSER and rtpproxy. Here I attach my command line for running rtpproxy ( 200.200.200.200 is my public IP of the OpenSER server host; I run rtpproxy on the same server).
-------------------------8X snip here------------------------------- # rtpproxy -f -l 200.200.200.200 -s unix:/var/run/rtpproxy.sock -r /home/rtpproxy -S /home/rtpproxy.work rtpproxy started, pid 24568 received command "V" sending reply "20040107 " received command "VF 20050322" sending reply "1 " received command "V" sending reply "20040107 " received command "V" sending reply "20040107 " received command "V" sending reply "20040107 " received command "V" sending reply "20040107 " received command "V" sending reply "20040107 " received command "V" sending reply "20040107 " received command "V" sending reply "20040107 " received command "V" sending reply "20040107 " received command "V" sending reply "20040107 " received command "V" sending reply "20040107 " received command "V" sending reply "20040107 " received command "VF 20050322" sending reply "1 " received command "V" sending reply "20040107 " received command "V" sending reply "20040107 " received command "V" sending reply "20040107 " received command "V" sending reply "20040107 " received command "V" sending reply "20040107 " received command "V" sending reply "20040107 " received command "V" sending reply "20040107 " received command "V" sending reply "20040107 " received command "V" sending reply "20040107 " received command "V" sending reply "20040107 " received command "V" sending reply "20040107 " received command "V" sending reply "20040107 " received command "V" sending reply "20040107 " received command "V" sending reply "20040107 " received command "V" sending reply "20040107 " received command "V" sending reply "20040107 " received command "V" sending reply "20040107 " received command "V" sending reply "20040107 " received command "V" sending reply "20040107 " received command "V" sending reply "20040107 " received command "V" sending reply "20040107 " received command "VF 20050322" sending reply "1 " received command "VF 20050322" sending reply "1 " received command "VF 20050322" sending reply "1 " received command "VF 20050322" sending reply "1 " received command "VF 20050322" sending reply "1 " received command "VF 20050322" sending reply "1 " received command "VF 20050322" sending reply "1 " received command "VF 20050322" sending reply "1 " received command "VF 20050322" sending reply "1 " received command "VF 20050322" sending reply "1 " received command "VF 20050322" sending reply "1 " received command "VF 20050322" sending reply "1 " received command "VF 20050322" sending reply "1 " received command "VF 20050322" sending reply "1 " received command "VF 20050322" sending reply "1 " received command "VF 20050322" sending reply "1 " received command "VF 20050322" sending reply "1 " received command "VF 20050322" sending reply "1 " received command "VF 20050322" sending reply "1 " received command "VF 20050322" sending reply "1 " received command "VF 20050322" sending reply "1 " received command "VF 20050322" sending reply "1 " received command "VF 20050322" sending reply "1 " received command "VF 20050322" sending reply "1 " received command "VF 20050322" sending reply "1 " received command "VF 20050322" sending reply "1 " received command "VF 20050322" sending reply "1 " received command "VF 20050322" sending reply "1 " received command "VF 20050322" sending reply "1 " received command "VF 20050322" sending reply "1 " received command "VF 20050322" sending reply "1 " received command "U 3331228473621-29341876517920@160.114.144.65 160.114.144.65 10004 196215176;1" new session 3331228473621-29341876517920@160.114.144.65 , tag 196215176;1 requested, type strong new session on a port 35000 created, tag 196215176;1 pre-filling caller's address with 160.114.144.65:10004 sending reply "35000 212.92.3.218 " session timeout RTP stats: 0 in from callee, 0 in from caller, 0 relayed, 0 dropped RTCP stats: 0 in from callee, 0 in from caller, 0 relayed, 0 dropped session on ports 35000/0 is cleaned up -------------------------8X snip here-------------------------------
My debug=7 output for OpenSER, filtered for the string "rtp" comes here (I had to chown openser.openser /var/run/rtpproxy* for OpenSER to make it possible to communicate with rtpproxy at all):
-------------------------8X snip here------------------------------- # tail -f daemon.log | grep rtp Jan 15 00:27:39 firewall openser: set_mod_param_regex: found <rtpproxy_sock> in module nathelper [/usr/lib/openser/modules/] Jan 15 00:27:39 firewall openser: set_mod_param_regex: found <rtpproxy_disable> in module nathelper [/usr/lib/openser/modules/] Jan 15 00:27:39 firewall openser: set_mod_param_regex: found <rtpproxy_disable_tout> in module nathelper [/usr/lib/openser/modules/] Jan 15 00:27:39 firewall openser: set_mod_param_regex: found <rtpproxy_tout> in module nathelper [/usr/lib/openser/modules/] Jan 15 00:27:39 firewall openser: set_mod_param_regex: found <rtpproxy_retr> in module nathelper [/usr/lib/openser/modules/] Jan 15 00:27:39 firewall openser: find_cmd_export_t: found <force_rtp_proxy>(0) in module nathelper [/usr/lib/openser/modules/] Jan 15 00:27:39 firewall openser: f<force_rtp_proxy> Jan 15 00:27:39 firewall /usr/sbin/openser[25093]: fixing force_rtp_proxy, line 443 Jan 15 00:27:39 firewall /usr/sbin/openser[25095]: rtpp_test: RTP proxy unix:/var/run/rtpproxy.sock found, support for it enabled Jan 15 00:27:40 firewall /usr/sbin/openser[25096]: rtpp_test: RTP proxy unix:/var/run/rtpproxy.sock found, support for it enabled Jan 15 00:27:40 firewall /usr/sbin/openser[25098]: rtpp_test: RTP proxy unix:/var/run/rtpproxy.sock found, support for it enabled Jan 15 00:27:40 firewall /usr/sbin/openser[25100]: rtpp_test: RTP proxy unix:/var/run/rtpproxy.sock found, support for it enabled Jan 15 00:27:40 firewall /usr/sbin/openser[25106]: rtpp_test: RTP proxy unix:/var/run/rtpproxy.sock found, support for it enabled Jan 15 00:27:40 firewall /usr/sbin/openser[25105]: rtpp_test: RTP proxy unix:/var/run/rtpproxy.sock found, support for it enabled Jan 15 00:27:40 firewall /usr/sbin/openser[25117]: rtpp_test: RTP proxy unix:/var/run/rtpproxy.sock found, support for it enabled Jan 15 00:27:40 firewall /usr/sbin/openser[25103]: rtpp_test: RTP proxy unix:/var/run/rtpproxy.sock found, support for it enabled Jan 15 00:27:40 firewall /usr/sbin/openser[25108]: rtpp_test: RTP proxy unix:/var/run/rtpproxy.sock found, support for it enabled Jan 15 00:27:40 firewall /usr/sbin/openser[25104]: rtpp_test: RTP proxy unix:/var/run/rtpproxy.sock found, support for it enabled Jan 15 00:27:40 firewall /usr/sbin/openser[25112]: rtpp_test: RTP proxy unix:/var/run/rtpproxy.sock found, support for it enabled Jan 15 00:27:40 firewall /usr/sbin/openser[25094]: rtpp_test: RTP proxy unix:/var/run/rtpproxy.sock found, support for it enabled Jan 15 00:27:40 firewall /usr/sbin/openser[25113]: rtpp_test: RTP proxy unix:/var/run/rtpproxy.sock found, support for it enabled Jan 15 00:27:40 firewall /usr/sbin/openser[25093]: rtpp_test: RTP proxy unix:/var/run/rtpproxy.sock found, support for it enabled Jan 15 00:27:40 firewall /usr/sbin/openser[25111]: rtpp_test: RTP proxy unix:/var/run/rtpproxy.sock found, support for it enabled Jan 15 00:27:40 firewall /usr/sbin/openser[25122]: rtpp_test: RTP proxy unix:/var/run/rtpproxy.sock found, support for it enabled Jan 15 00:27:40 firewall /usr/sbin/openser[25118]: rtpp_test: RTP proxy unix:/var/run/rtpproxy.sock found, support for it enabled Jan 15 00:27:40 firewall /usr/sbin/openser[25123]: rtpp_test: RTP proxy unix:/var/run/rtpproxy.sock found, support for it enabled Jan 15 00:27:40 firewall /usr/sbin/openser[25097]: rtpp_test: RTP proxy unix:/var/run/rtpproxy.sock found, support for it enabled Jan 15 00:27:40 firewall /usr/sbin/openser[25107]: rtpp_test: RTP proxy unix:/var/run/rtpproxy.sock found, support for it enabled Jan 15 00:27:40 firewall /usr/sbin/openser[25125]: rtpp_test: RTP proxy unix:/var/run/rtpproxy.sock found, support for it enabled Jan 15 00:27:40 firewall /usr/sbin/openser[25120]: rtpp_test: RTP proxy unix:/var/run/rtpproxy.sock found, support for it enabled Jan 15 00:27:40 firewall /usr/sbin/openser[25115]: rtpp_test: RTP proxy unix:/var/run/rtpproxy.sock found, support for it enabled Jan 15 00:27:40 firewall /usr/sbin/openser[25110]: rtpp_test: RTP proxy unix:/var/run/rtpproxy.sock found, support for it enabled Jan 15 00:27:40 firewall /usr/sbin/openser[25119]: rtpp_test: RTP proxy unix:/var/run/rtpproxy.sock found, support for it enabled Jan 15 00:27:40 firewall /usr/sbin/openser[25116]: rtpp_test: RTP proxy unix:/var/run/rtpproxy.sock found, support for it enabled Jan 15 00:27:40 firewall /usr/sbin/openser[25124]: rtpp_test: RTP proxy unix:/var/run/rtpproxy.sock found, support for it enabled Jan 15 00:27:40 firewall /usr/sbin/openser[25114]: rtpp_test: RTP proxy unix:/var/run/rtpproxy.sock found, support for it enabled Jan 15 00:27:40 firewall /usr/sbin/openser[25121]: rtpp_test: RTP proxy unix:/var/run/rtpproxy.sock found, support for it enabled Jan 15 00:27:40 firewall /usr/sbin/openser[25099]: rtpp_test: RTP proxy unix:/var/run/rtpproxy.sock found, support for it enabled Jan 15 00:27:40 firewall /usr/sbin/openser[25102]: rtpp_test: RTP proxy unix:/var/run/rtpproxy.sock found, support for it enabled Jan 15 00:27:40 firewall /usr/sbin/openser[25109]: rtpp_test: RTP proxy unix:/var/run/rtpproxy.sock found, support for it enabled Jan 15 00:27:40 firewall /usr/sbin/openser[25101]: rtpp_test: RTP proxy unix:/var/run/rtpproxy.sock found, support for it enabled Jan 15 00:28:21 firewall /usr/sbin/openser[25112]: force_rtp_proxy2: proxy reply: 35000 212.92.3.218 Jan 15 00:28:27 firewall /usr/sbin/openser[25114]: build_res_from_sip_res: copied size: orig:77, new: 16, rest: 780 msg= SIP/2.0 200 Ok^M Via: SIP/2.0/UDP 160.114.144.65:1024;branch=z9hG4bK27994379851422672^M From: 06212527755 sip:06212527755@sip.ephone.hu:5060;tag=196215176^M To: 06212527722 < sip:06212527722@sip.ephone.hu:5060>;tag=7816428^M Contact: < sip:06212527722@160.114.144.65:5060>^M Record-Route: sip:200.200.200.200;lr;ftag=196215176^M Call-ID: 3331228473621-29341876517920@160.114.144.65^M CSeq: 1 INVITE^M Content-Type: application/sdp^M Server: X-Lite release 1105d^M Content-Length: 320^M ^M v=0^M o=06212527722 2057424946 2057430520 IN IP4 160.114.144.65^M s=X-Lite^M c=IN IP4 160.114.144.65^M t=0 0^M m=audio 8000 RTP/AVP 0 8 3 98 97 101^M a=rtpmap:0 pcmu/8000^M a=rtpmap:8 pcma/8000^M a=rtpmap:3 gsm/8000^M a=rtpmap:98 iLBC/8000^M a=rtpmap:97 speex/8000^M a=rtpmap:101 telephone-event/8000^M a=fmtp:101 0-15^M a=sendrecv^M -------------------------8X snip here-------------------------------
My nathelper related part of openser.cfg comes here:
-------------------------8X snip here------------------------------- loadmodule " nathelper.so" modparam("nathelper", "natping_interval", 60) modparam("nathelper", "ping_nated_only", 1) modparam("nathelper", "received_avp", 42) modparam("nathelper", "rtpproxy_sock", "unix:/var/run/rtpproxy.sock") modparam("nathelper", "rtpproxy_disable", 0) modparam("nathelper", "rtpproxy_disable_tout", 60) modparam("nathelper", "rtpproxy_tout", 1) modparam("nathelper", "rtpproxy_retr", 5) modparam("nathelper", "sipping_method", "OPTIONS") -------------------------8X snip here-------------------------------
Of course, directories /home/rtpproxy* are empty.
Could somebody please help me why there is no media stream between OpenSER and rtpproxy?
Your help is greatly appreciated in advance. I am using Debian Etch.
Best regards, Zoltan
Kovács Zoltán schrieb:
...
Could somebody please help me why there is no media stream between OpenSER and rtpproxy?
Between Openser and rtpproxy is no media traffic, just the proprietary rtpproxy protocol which is used by nathelper module to control the rtpproxy.
Nevertheless it looked like there was no media stream between the SIP client and the rtpproxy.
+-------+ +-------+ | |<---SIP---->|SIP | | | |Proxy | | | | | | | +-------+ | SIP | ^ | Client| | proprietary RTPPROXY protocol | | v | | +-------+ | | |RTP | | |<---RTP---->|Proxy | +-------+ +-------+
1. Use ngrep to inspect the SIP message: - look if the IP address in the c line in the SDP is replaced with the rtpproxy's IP address and the port number is replaced with the port number allocated by rtpproxy
2. use tcpdump/wireshark/.... to verify if there are RTP packets sent to your server. MAybe there is a firewall which blocks RTP packets.
regards klaus
Dear Klaus,
Between Openser and rtpproxy is no media traffic, just the proprietary
rtpproxy protocol which is used by nathelper module to control the rtpproxy.
thank you for the clarification.
1. Use ngrep to inspect the SIP message:
Using debug=7 I think I saw in the openser log that the c line was not replaced.
2. use tcpdump/wireshark/.... to verify if there are RTP packets sent to
your server. MAybe there is a firewall which blocks RTP packets.
I opened all ports so it shouldn't have been a problem.
Very fortunately I started on this trace you suggested. I tried to merge the nathelper.cfg file (shipped with openser as a factory documentation) with my openser.cfg. And voilá, it seems to work smoothly! :-D
Thank you for your kind help!
Best regards, Zoltan
I report that everything works now well. Only one thing remained: the media stream is not put to the directory I entered. What's more, I cannot see any real open files in /proc/`cat /var/run/rtpproxy.pid`/fd --- just a few links to sockets. Am I missing something here?
TIA and best regards, Zoltan
Dear Maxim, Race and the OpenSER community,
I realized that rtpproxy does not start to record the RTP stream only if it is asked by OpenSER (or other external software). Googling the web I found http://lists.iptel.org/pipermail/semsdev/2006-October/000768.html which uncovers some facts about the missing feature of sending the "R" command --- it is not present in OpenSER-1.1.x as far as I know. Is it there in 1.2.x or 1.3.x?
In addition, I learned that the rtpproxy source also needs some editing to make the recording work. Race Vanderdecken started some kind of development back in 2006. Race, could you please give an outline of the status of your improvements? Are the changes put back into the official version of rtpproxy? (I am afraid the answer is no.) Finally, my last question is if using SEMS (I'm completely new to this software), am I going to get a complete solution for my problem?
Thank you in advance for trying to answer my questions.
Best regards, Zoltan
2008/1/25, Kovács Zoltán kovzol@matek.hu:
-
Klaus Darilion -
Kovács Zoltán