[asterisk-biz] Solving DTMF issue

[Trixter aka Bret McDanel]

On Wed, 2008-04-02 at 23:54 -0400, Peter Beckman wrote:
>   Why don't you release your patch under a different license, so I can patch
>   it separately from Asterisk?  I can make modifications to Asterisk, I
>   don't have to make them public.

it really isnt that hard for anyone to replicate it, you just get the
rfc, get a packet sniffer, look at the traffic and it was all fairly
obvious stuff.  At one time I gave exact details which were to be put
into the comments of a bug that was then already filed and open and just
idling on bugs.digium.com (I really dont recall which number though, I
*think* it ended in 088 for some reason but cant say why).

My patch did a couple other things as well that were unrelated to fixing
problems, such as making the code far easier to read and understand.  I
created proper structures for the rtp headers and 2833 info, that way
you dont have to access it as an array and do some logical operators to
deal with less than even 8 bit multiple sizes (there are some oddly
sized items, not dissimilar to IP header length and version where they
are each one nybble).  It was just painful to work with "out of the box"
so the cleanup was to make it easier to fix.

This of course was all months ago, I want to say that it was last year
even, but I just dont recall when exactly. 

But take heart, freeswitch has the same problem, and they are also
unwilling to fix the same issue because "it goes the wrong direction",
although my thoughts at the time that was said was they didnt understand
nor care to understand what the problem was.  Why if you look at the
freeswitch rtp stack, you will see a high number of similarities to the
asterisk one, and its odd that the same bugs were replicated across,
almost as if someone just copied the code, did some clean up, changed
some names of variables and such and called it their own work.  I am not
saying that is what happened, but it sure seems like it - why would a
"from scratch" work have the same errors in it?


So you arent alone in this issue.  And there are still incompatibilities
with really strict gateways, to the point that it does not work at all
with those gateways.  It could be worse right?  Could be metaswitch
where you can DoS it (hose the DSPs, cause resets, destabilize the
switch) with bad 2833 data :) 

-- 
Trixter http://www.0xdecafbad.com     Bret McDanel
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