IAX2 Bridge Failing

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Asterisk Users 7 Comments

I am trying to connect an IAX ATA to an Asterisk system. The Asterisk system has been stable for years, and has no trouble bridge SIP phone sets to IAX trunks.

When I initiate a call from the IAX ATA, something goes wrong. One rare occasion it works fine, but usually there is no audio passed. I have a snippet of the console below. Notice no bridging message…not sure if that’s a clue? The dialplan seems to execute properly, and I can watch the destination system which answers the call and starts playing media (monkeys) which I don’t hear.

Any ideas on what is going on? Since this is IAX in and IAX out, NAT should not be an issue (even through there is NAT on both sides). Since media moves on the same UDP port as call setup, also proves should not be a network problem (I think)

Can someone point me to a solution?


(IP’s and ISP and phone number disguised)

– Executing [s@macro-dialexternal:57] GotoIf(“IAX2/S-14468”, “1?dialnormal”) in new stack
— Goto (macro-dialexternal,s,60)
— Executing [s@macro-dialexternal:60] Dial(“IAX2/S-14468”, “IAX2/ISP123/1234567890|60|W”) in new stack
— Called ISP123/1234567890
— Call accepted by (format ulaw)
— Format for call is ulaw
— IAX2/ISP123-2261 answered IAX2/S-14468
— Channel ‘IAX2/S-14468’ ready to transfer
— Channel ‘IAX2/ISP123-2261’ ready to transfer
— Hungup ‘IAX2/ISP123-2261’

7 thoughts on - IAX2 Bridge Failing

  • Some more details…I noticed that the call is bridged, and audio goes one way. However, the dial command still times out after 35 seconds (approx), and exists non-zero.

    While the channels are up, I did an core show channel xxx and found Blocking in:

    Is this a bug? Or something I can fix through config?

  • Michelle Dupuis wrote:


    Set “transfer=no” under the entries in iax.conf for the peers/users/friends/etc in question, reload, retry, and see if that changes the behavior. If it does then something involved may not like IAX2 native transfers.


  • I tried transfer=no, transfer=yer, and transfer=mediaonly (with a “reload” inbetween)….same result

    I agree it sounds like something either end is using the wrong IP/port address somewhere in the call (yet signalling works fine).

    Anything else to suggest? I was hoping for an externalip type setting but not in iax2 (at least not in 1.4.x.x)

  • Did you change your network switch recently? Some Digium IAX ATAs do not behave well with Cisco equipment.

  • No – but this is a new setup so I can’t say it worked before…it just isn’t working from the start.

    I’ve found the call setup works and once bridged there is one way audio (to the ATA, none from the ATA). And the the connection drops after 30 secs approx because something on the path (or endpoint) realizes something is wrong…