[Asterisk-Users] Re: How far is IAX to be a Standard

[niels at wxn.nl]

Hello

IAX really isn't the 'one and only' perfect signaling protocol because
many people forget one thing

IAX has one technical issue (by design) which makes it difficult to ever
get accepted by the big boys, a real big problem for carriers who have
big loads on their systems like we do.

With IAX the audio (RTP) and signaling goes embedded over one port. We
all know that the big advantage ofcourse is that this makes it an
excellent performer behind a NAT, but the big disadvantage is that there
is not any DSP chip available in the market which is able to get the
codecs encoded and put into this embedded rtp+signaling channel, and I
wander if there ever will be because another piece of software does the
signaling (asterisk in this case) asterisk would have to 'tell' the DSP
chip the signaling packets to embed into the IAX/RTP channel.. That
would be a whole new DSP standard, Will any chipmaker (besides digium)
ever see the need to design such a chip?

Anyhow, the situation now, is that there is no DSP chip, that means ..
Your main processor has to encode the channel in total (3 to 4 E1's
absolute is the max possible with dual xeon 3 ghz I read somewhere in
this case) 

Another method is to send the incoming IAX on asterisk out again with
SIP to a gateway with hardware DSP's.. (like we do).. This needs less
performance ofcourse because asterisk doesn't have to do codec encoding,
but nevertheless will still have to transcode to get the signaling and
RTP merged and submerged from/to this one IAX port to separate
Signaling/RTP ports.. Our setup now is the second scenario.. And my
first (rough) calculations are that a dual xeon 3.0 ghz can handle about
500 concurrent channels in this scenario...

Ever wandered why there isn't any codec (DSP) hardware availiable for
asterisk?? I think here is the answer, because it is very hard to make,
Digium should then be able to design a totally new DSP chip design ..
And that's much more difficult than to design an E1 board. 

Our case is that we have about 200 E1's of voip (h323 and sip) traffic
and are still expanding. If we would have this all on IAX this would be
unmanageable, we would need 50 linux boxes.

Conclusion.. IAX Is a good performer behind NAT and perfect for small
setups but to work in an enterprise, Much work has to be done.

Niels.


-----Original Message-----
From: asterisk-users-bounces at lists.digium.com
[mailto:asterisk-users-bounces at lists.digium.com] On Behalf Of Michael
Giagnocavo
Sent: Monday, November 01, 2004 11:13 PM
To: 'Asterisk Users Mailing List - Non-Commercial Discussion'
Subject: RE: [Asterisk-Users] Re: How far is IAX to be a Standard

Unless SIP just plain does not work, I think it'll be hard (for IAX to
get excellent acceptance), without a lot of good marketing and other
efforts by Digium. At VON, only a few people even understood what
Asterisk was, let alone even had heard of IAX. 

Even with IT people controlling things you still see a lack of good
decisions. How many people do SSL POP3? How many people use S/MIME? All
very simple things that don't require reworking of dedicated hardware or
huge industry efforts. 

My only point is that we can't just rely on a better design to somehow
magically win out. Getting Digium to create a standard with input from
other vendors would be a huge plus and help pave the path forward.

-Michael

-----Original Message-----
From: asterisk-users-bounces at lists.digium.com
[mailto:asterisk-users-bounces at lists.digium.com] On Behalf Of Steve
Totaro
Sent: Monday, November 01, 2004 12:39 PM
To: Asterisk Users Mailing List - Non-Commercial Discussion
Subject: Re: [Asterisk-Users] Re: How far is IAX to be a Standard

I see your point and it is well taken but I feel that with convergence
you are going to see more IT staff in charge of phone systems.  In turn,
I see more research and informed decisions going on, not just a consumer
following

what is being pushed.

That being said, maybe I am just looking at a grey sky through blue
sunglasses.



> >From: asterisk-users-bounces at lists.digium.com
> [mailto:asterisk-users->bounces at lists.digium.com] On Behalf Of Steve 
> Totaro
>
>>I predict a paradigm shift, rendering what is historical, null.
>
> Is this in general, applying to all technology, or just to telecom?
(i.e.,
> will Hollywood ship videos in hi-def on EVD?)
>
> -Michael
>
>> >No worries here.  What works best will win out eventually.
>>
>> Not sure where you get that idea, as historically it's not that way
:S.
>>
>> Companies will make SIP work reasonably enough. What will win out is
>> whatever is marketed and sold the best. Getting published specs, inc.
>> being
>> a published "standard" is part of that marketing.
>>
>> -Michael
>>
>> ----- Original Message ----- 
>> From: "Randy Bush" <randy at psg.com>
>> To: "Voip Business" <voipbusiness at gmail.com>
>> Cc: <Asterisk-Users at lists.digium.com>
>> Sent: Monday, November 01, 2004 12:44 PM
>> Subject: [Asterisk-Users] Re: How far is IAX to be a Standard
>>
>>
>>>> what does the RFC's guys and the Pseudo-Cisco IETF think about this
>>>> Protocol?
>>>
>>> the internet vendor task force has a massive amount invested in
>>> sip.  so there will be a lot of 'guidance' to have it published
>>> as an informational rfc.  if iax catches on in the market, then
>>> they'll have to play.  otherwise, expect to have a hard time
>>> getting iax on the ivtf standards track.
>>>
>>> randy
>>>
>>> 
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