[Asterisk-Users] No incoming audio on incoming SIP calls

[Johan Landerholm]

Hi Dave,

Long time no see...

I have been looking at the various packets going in/out of my network with
regards to my SIP phones.
I usually use the ethereal network sniffer on my network and it has
wonderful support for SIP/RTP/RTSP/SDP analysing.
In the setup phase of a call the RTP packet shows exactly what IPs and
ports that your call is supposed to use.
When I have these problems, I sniff the network and it shows a private IP
instead of the public (external) IP in the voice data stream. Then it's
easy to see what needs to be fixed.
What kind of router/firewall do you use ?

I can send you some examples later on tonight if you need them.

Best regards,
Johan Landerholm, Stockholm, Sweden
(ex. SCO)

> Now this is really frustrating. Everything was working fine, and now it
> isn't ... I don't think I've changed anything that would affect this, but
> I
> guess you never can be too sure.
>
> My setup is as follows:
>
> SIP softphone (SJphone) connected to Asterisk running my Linux NAT
> firewall
> box. This is all on the internal network.
>
> Asterisk then dialing out through various means - SIP to Stanaphone, FWD,
> Gossiptel and PSTN via an X100P.
>
> For incoming calls, an 0870 number from CallUK routes to my FWD account,
> and
> an 0870 number from Gossiptel routing to my Gossiptel account.
>
> Outbound calls all work fine ... I get audio in both directions, no
> problem.
>
> Incoming calls on either 0870 number connect fine, and audio goes from the
> softphone to the caller, but not the other way ... I hear no audio on the
> softphone from the caller's phone.
>
> I'm getting no alerts from my firewall that it's dropping anything.
>
> I know my way around packet sniffers, but I don't know what to look for
> here. What should the inbound audio packets look like?
>
> Thanks
>
>
> --
> David Gurr
> Congruity Ltd.
> Hemel Hempstead, UK
>
> _______________________________________________
> Asterisk-Users mailing list
> Asterisk-Users at lists.digium.com
> http://lists.digium.com/mailman/listinfo/asterisk-users
> To UNSUBSCRIBE or update options visit:
>    http://lists.digium.com/mailman/listinfo/asterisk-users
>