Asterisk IAX2: Separate Signaling and Media

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Asterisk Users 4 Comments

Supposedly, IAX2 now has the ability to operate with signaling and media in separate streams, very much like SIP. I’ve read about this feature here[1] and there[2], but I have yet to see how to actually implement or test it. There are no options in the iax.conf sample configs with Asterisk.

All suggestions welcome, except those telling me to jump off a bridge because separated signaling and media makes IAX pointless when compared to SIP. 🙂


4 thoughts on - Asterisk IAX2: Separate Signaling and Media

  • I believe you are misinterpreting the RFC. IAX2 cannot use a separate
    signaling and media stream to setup a call, but it *can* optimize a
    media stream for a bridged call so that the media does not have to make
    as many hops as the signaling does. The media still moves on the same
    ports as the signaling packets, using the same protocol.

  • And in that case the options are:

    transfer=no ; Disable IAX native transfer
    ;transfer=mediaonly ; When doing IAX native transfers, transfer
    ; only media stream

    Well, it depends on what version. The above is from a 1.4 system –
    earlier systems had notransfer=yes, but not the mediaonly option.

  • I think that the only implementation that does this is in asterisk.
    It only does it in a limited way by setting:
    in iax.conf

    I’ve never tried it, but I’d be happy to co-operate on an experiment 🙂


    Tim Panton – Web/VoIP consultant and implementor