[Asterisk-Users] IAX/Grandstream.

[steve at daviesfam.org]

On Tue, 5 Oct 2004, Benjamin on Asterisk Mailing Lists wrote:

> Manufacturers of existing phones would seem to have a head start if
> they intend to support IAX through a custom firmware. One of the
> manufacturers I know to be working on IAX firmware is a company in a
> neighbouring country of where I am. I believe they will be *able* to
> release their firmware before the end of the year, but whether they
> will actually do so, that I do not know.
> 
> Yet, taking into account that IAX has become far more widespread, that
> there is a clear demand, that there is now talk about an IAX RFC, that
> at least one chipmaker seems committed to incorporate IAX into the
> next version of their chipset regardless of how low end that chip may
> be, it would seem to me that we will see a turning point next year.


Hi Ben, others,

There are plenty of subtleties to the IAX protocol, especially with regard 
to:

  - the use and meaning of timestamps in the different IAX frame types.
  - the correct recovery of miniframe timestamps, especially in situations
    where full-frame VOICE frames are lost (which happens with IAX native 
    bridging)
  - trunking

These need to be coded carefully.  If they aren't coded carefully, things
still mostly work - certainly calls can be established - but issues are
introduced with dejittering, with further native bridging of the call and
so forth.

There is no formal and/or complete spec for IAX.  So - who is testing
interoperability, and checking all these subtleties?

There can't be that many people who understand all these tricky bits and 
can say whether these new implementations work properly.

Does Mark have beta of these phones?  I'd also be prepared to evaluate 
betas - which can be done simply by registering the phone to one of my 
boxes and making various test calls and reviewing the iax2 debug logs.

Regards,
Steve Davies