[OpenSIPS-Users] Change in SDP/RTP routing with Opensips 1.4 and 1.6

Chris Stone axisml at gmail.com
Tue Feb 8 21:58:13 CET 2011


On Tue, Feb 8, 2011 at 1:16 PM, Ovidiu Sas <osas at voipembedded.com> wrote:
> Based on your description, it seems that you are dealing with a weird
> firewall/NAT that is SIP aware.
> Also, I don't know if this is a typo, but you are forwarding with
> opensips to and your INVITE is actually sent to
> Try to turn off the firewall and NAT ans see it this is fixing your issue.

No firewall - though of that too at first. There is a PIX between the
net and the servers, but not between the Opensips server and the
Asterisk server. The packet capture showing the modifications to the
INVITES was from the Opensips server - in-n-out. No firewall involved
at that point.

The Opensips server is and it's forwarding to the
Asterisk server which is at

Due to previous issues with the sip fixup in PIX firewalls, that it
disabled in the PIX we're using. But again, this modification is being
done after the PIX hands it off to the Opensips server....



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