[Asterisk-Dev] I need help to make a simple iax switch/proxy

[Derek Smithies]

Steve,
 I was enquiring:
  is it a protocol problem,
  or an implementation problem,
  or both.

Your letter does not suggest a cause of the various problems. let us do 
the developer thing and have a healthy debate about the real problem.

In my opinion:
Having carefully reviewed the asterisk IAX2 implementation 
   (which I used to explain the finer points of the protocol)
and having written a C++/cross platform/OPAL based IAX2 implementation,
I am of the view that the quality issues you describe are implementation 
difficulties. There is nothing (in my view) in the protocol that can 
explain the distortion and cutoff issues that you report.

Specifically, more threads are required to make the asterisk IAX2 
implementation work nicely. One thread is required to transmit packets 
that have been assembled by the generating thread,
and a second thread is required to receive packets (but not process 
packets) from the remote nodes. With more threads, the asterisk IAX2 
implementation will work nicely on a multi CPU box under load.

You see, implementing IAX2 as is done is asterisk is unfortunate, cause 
there is a serious bottle neck at the reception and transmission of 
packets. The receive thread has to do reception and decoding of the 
packets, leaving insufficient time to do correctly receive all packets.



Derek.
==============================================================

in a hight On Sun, 11 Sep 2005, Steve wrote:

> I agree with you Derek. I was stating my Opinion, Which happens to be a fact
> as well, that IAX does have alot of problems in a MAJOR implementation. But,
> SIP Seems to be a more strategic way of doing things yet, until something is
> done to help IAX become more of a acceptable method of doing VOiP
> Communications. Yet until IAX is dealt with and maybe re-structured to
> provide better audio quality and not so much distortion and cutoff during a
> call session. I think it would be best at this time for people who are more
> into the quality of the VOiP Conversation to rely on sip until things can be
> fixed with IAX2.
> 
> Stephen McMahon
> DDIS
> WV762H18
> 
> ----- Original Message ----- 
> From: "Derek Smithies" <derek at indranet.co.nz>
> To: "Asterisk Developers Mailing List" <asterisk-dev at lists.digium.com>
> Sent: Thursday, September 08, 2005 3:13 PM
> Subject: Re: [Asterisk-Dev] I need help to make a simple iax switch/proxy
> 
> 
> > Steven da ass,
> >   You never know - some people are going to provide some useful help
> >   which is why I always try to be nice (and never call people trolls).
> >
> >  It was possible that the person would reply with a reasonable answer.
> >
> >  And, it also helped raise the knowledge level of *-devel people.
> >   we need to differentiate beween the protocol, and the implementation.
> >
> >
> > Derek.
> > ==================================
> > On Thu, 8 Sep 2005, Steven ASSfield wrote:
> >
> > > On Fri, 2005-09-09 at 09:45 +1200, Derek Smithies wrote:
> > > > Hi,
> > > >  Stave, thanks for your comments.
> > >
> > > >
> > > > Now you wrote:
> > > > > Why does IAX suck? Because it does. Dont question my authority
> > > >
> > > > I am sorry, this is not helpful. If we can find the cause of the
> > > > "suckiness", we can fix the suckiness. Comments such as yours above do
> not
> > > > help.
> > >
> > > Please don't feed trolls. The "Dont question my authority" was a pretty
> > > obvious hint that it was a blatant troll/humerus post.
> > >
> >
> > -- 
> > Derek Smithies Ph.D.                 Any fool can write code that
> > IndraNet Technologies Ltd.                a computer can understand.
> > Email: derek at indranet.co.nz         Good programmers write code
> > ph +64 3 365 6485                          that humans can understand.
> > Web: http://www.indranet-technologies.com/            Martin Fowler
> >
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-- 
Derek Smithies Ph.D.                 Any fool can write code that 
IndraNet Technologies Ltd.                a computer can understand.        
Email: derek at indranet.co.nz         Good programmers write code 
ph +64 3 365 6485                          that humans can understand.
Web: http://www.indranet-technologies.com/            Martin Fowler