[Asterisk-Dev] IAX Spec online

[Tilghman Lesher]

On Tuesday 26 April 2005 22:52, Kenny Shumard wrote:
> I've finished a working version of the IAX specification and posted
> it online at
>
> http://splurge.peoples-wireless.com/iax/iax.txt
>
> I'm very willing to listen to constructive criticism regarding
> additions or alterations to the spec as presented. The more people
> that read and comment on this, the sooner we can (hopefully) get it
> into the official standards track.
>
> I know there are some parts that aren't completely correct, so
> please help me out by pointing them out -- gently. : )

A couple thoughts:

You may want to notate somewhere in this document that the protocol
that you have labelled IAX is actually commonly known as IAX2.
Otherwise, this is likely to be a source of confusion.

In the table on pages 33-35, it would be helpful to include an
argument octet size next to each IE type.  For example, IE 42
(CAUSECODE) takes a single octet as an argument, while IE 21
(CALLNO) takes two octets.  I realize the information is included
in each of the descriptions, but as long as you're including a table,
that summary information is most helpful.

IE 16 specifies an MD5 result without actually specifying what
specific information, in what order, is to be hashed.  I mention
this specifically because there is a criticism (in the Asterisk code
itself) that the SIP spec does not include an example of what is to be
hashed.

It should be explicitly stated that for multi-byte encoded numbers,
the format should be Network Order.

Also, I believe that CAUSECODE _should_ be sent with any frame
containing a CAUSE IE.  The CAUSE IE is good for spitting out error
messages on the console and into logs, but CAUSECODE is far more
useful programatically, considering it has a limited number of values,
each of which are well-defined (and can be subsequently passed to
other types of channels without translation).

-- 
Tilghman