[Users] force_rtp_proxy() problem.

Ray Van Dolson rayvd at digitalpath.net
Tue Aug 2 23:51:52 CEST 2005

Thanks for the help earlier Bogdan.

I've gotten things working for the most part, but am having a problem with the
force_rtp_proxy function.

Once again, here is my setup:


 - eth0:
 - eth1:

 - eth0:
 - eth1:

Yes, Asterisk and OpenSER are on the same Private network currently.  This is
just for testing as clients were originally connecting directly to Asterisk.
It will not always be the case.

I have registration working correctly.

If my SIP ATA makes an outbound call (INVITE) it appears to inform Asterisk in
its SDP payload that media traffic (RTP) should be sent back to (on
eth1).  Asterisk has no problem with this since it also has an IP on the network.  However this obviously will not always be the case.  I
want media (RTP) to travel back via the eth0 IP addresses.

I've tried the following:

  force_rtp_proxy("", "")

To hopefully force my media address to be the IP on eth0 on OpenSER.  However,
calls no longer succeed and I see the following in the SDP payload now:

o=- 1298429 1298429 IN IP4
c=IN IP4
t=0 0
m=audio 3508835088 RTP/AVP 0 2 4 8 18 96 97 98 100 101
a=rtpmap:0 PCMU/8000
a=rtpmap:2 G726-32/8000
a=rtpmap:4 G723/8000
a=rtpmap:8 PCMA/8000
a=rtpmap:18 G729a/8000
a=rtpmap:96 G726-40/8000
a=rtpmap:97 G726-24/8000
a=rtpmap:98 G726-16/8000
a=rtpmap:100 NSE/8000
a=rtpmap:101 telephone-event/8000
a=fmtp:101 0-15

As you can see, the info in c= has both IP's and they are not seperate by a
space.  This same phenomenon occurs even if I use force_rtp_proxy by itself or
with any of the flags.

Normally there is just one IP address in this field it seems.

Is this a bug in force_rtp_proxy or am I doing something incorrectly?


Ray Van Dolson
Linux/Unix Systems Administrator
Digital Path, Inc.

More information about the sr-users mailing list