Re: [Users] openser and rtpproxy on multihomed host - sr-users

5 Jun 2007

On 06/05/2007 05:17 PM, raviprakash sunkara wrote:
...
  Hi Alexander
 Can use fix_nated_sdp("flag"); and also  force_rtp_proxy("flags");

I'm already using force_rtp_proxy() (without arguments) and it already
rewrites the "c=" address in the sdp information but it uses the wrong
interface address. (The openser-server/rtpproxy has two IP adresses in
the same subnet.)

Since I know the address which is used by the clients or contacting the
server, I could hardcode the address as the second parameter to
force_rtp_proxy to force the use of this address but I was looking for a
cleaner solution.

I'd like to use the address where the SIP request came in for both RTP
streams. Maybe I can use the pseudo-variable $Ri (Received IP address)
as the second parameter to force_rtp_proxy? This should force the use of
 the correct IP address in the "c=" field and will hopefully persuade
the client to use this IP address as the destination address for its RTP
data. But how do I tell rtpproxy to send its RTP data from this address?

Thanks,
--leo

...
  On 6/5/07, Alexander Bergolth
&lt;leo(a)strike.wu-wien.ac.at&gt; wrote:

 Hi!

 I'm experiencing problems using openser and rtpproxy on a multihomed box
 (IP addresses are 137.208.89.45 and 137.208.89.65).

 The client (firewalled) contacts the server via the first IP address
 (137.208.89.45) but rtpproxy sometimes uses it's second IP
 (137.208.89.65) in the "c=" SDP-information. (See below.)
 However it _sends_ RTP packets from the _first_ IP address. Those
 packets will never pass through the firewall, of course, since the
 clients outgoing RTP traffic is sent to another IP address than the
 incoming traffic is hitting the firewall from.

 Is there a way to tell rtpproxy to use the same IP-address both for the
 c= SDP header and as source address?

 -------------------- 8< --------------------
 ##
 T 2007/06/05 15:57:36.041537 137.208.89.45:5060 ->
 137.208.90.164:3099[AP]
 SIP/2.0 183 Session Progress.
 Via: SIP/2.0/TCP
 137.208.90.164:56136
 ;branch=z9hG4bK-d87543-a107a77a6311422d-1--d87543-;rport=3099.
 From: "Alexander Bergolth"<sip:30001@wu-wien.ac.at>;tag=5b6d7b31.
 To: "996050"<sip:996050@wu-wien.ac.at>;tag=as2e40807f.
 Call-ID: MTVjYzlhMDdjMjAwODExZDEyNzk5M2IwN2UxNjhlYTc..
 CSeq: 2 INVITE.
 User-Agent: Asterisk PBX.
 Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, SUBSCRIBE, NOTIFY.
 Supported: replaces.
 Contact: <sip:996050@137.208.89.135>.
 Content-Type: application/sdp.
 Content-Length: 283.
 .
 v=0.
 o=root 6978 6978 IN IP4 137.208.89.135.
 s=session.
 c=IN IP4 137.208.89.65.
 t=0 0.
 m=audio 35064 RTP/AVP 0 8 101.
 a=rtpmap:0 PCMU/8000.
 a=rtpmap:8 PCMA/8000.
 a=rtpmap:101 telephone-event/8000.
 a=fmtp:101 0-16.
 a=silenceSupp:off - - - -.
 a=ptime:20.
 a=sendrecv.
 a=nortpproxy:yes.
 -------------------- 8< --------------------

 -------------------- 8< --------------------
 15:57:35.814136 IP 137.208.90.164.3099 > 137.208.89.45.5060: P
 4236850032:4236851080(1048) ack 224540451 win 64256
 15:57:35.814147 IP 137.208.89.45.5060 > 137.208.90.164.3099: . ack 1048
 win 2003
 15:57:35.814351 IP 137.208.89.45.5060 > 137.208.90.164.3099: P
 1:550(549) ack 1048 win 2003
 15:57:35.814430 IP 137.208.89.45.5060 > 137.208.90.164.3099: P
 550:1264(714) ack 1048 win 2003
 15:57:35.814850 IP 137.208.90.164.3099 > 137.208.89.45.5060: . ack 1264
 win 64177
 15:57:35.915829 IP 137.208.90.164.3099 > 137.208.89.45.5060: P
 1048:1418(370) ack 1264 win 64177
 15:57:35.955948 IP 137.208.89.45.5060 > 137.208.90.164.3099: . ack 1418
 win 2003
 15:57:36.017309 IP 137.208.90.164.3099 > 137.208.89.45.5060: P
 1418:2672(1254) ack 1264 win 64177
 15:57:36.017320 IP 137.208.89.45.5060 > 137.208.90.164.3099: . ack 2672
 win 2003
 15:57:36.017397 IP 137.208.89.45.5060 > 137.208.90.164.3099: P
 1264:1813(549) ack 2672 win 2003
 15:57:36.018604 IP 137.208.89.45.5060 > 137.208.90.164.3099: P
 1813:2388(575) ack 2672 win 2003
 15:57:36.019170 IP 137.208.90.164.3099 > 137.208.89.45.5060: . ack 2388
 win 64256
 15:57:36.041454 IP 137.208.89.45.35064 > 137.208.90.164.10676: UDP,
 length 172
 15:57:36.041537 IP 137.208.89.45.5060 > 137.208.90.164.3099: P
 2388:3200(812) ack 2672 win 2003
 15:57:36.046899 IP 137.208.90.164.10677 > 137.208.89.65.35065: UDP,
 length 132
 15:57:36.061155 IP 137.208.89.45.35064 > 137.208.90.164.10676: UDP,
 length 172
 15:57:36.080128 IP 137.208.90.164.10676 > 137.208.89.65.35064: UDP,
 length 172
 15:57:36.081157 IP 137.208.89.45.35064 > 137.208.90.164.10676: UDP,
 length 172
 [...]
 -------------------- 8< --------------------

 Thanks in advance,
 --leo

 P.S.: I'm using openser-1.2 and rtpproxy-cvs20070222.

 -- 
 e-mail   ::: Alexander.Bergolth (at) wu-wien.ac.at
 fax      ::: +43-1-31336-906050
 location ::: Computer Center | Vienna University of Economics | Austria

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-- 
e-mail   ::: Alexander.Bergolth (at) wu-wien.ac.at
fax      ::: +43-1-31336-906050
location ::: Computer Center | Vienna University of Economics | Austria