[asterisk-bugs] [Asterisk 0010530]: DTMFs passing only in part between two asterisk machines with an IAX2 connection

[noreply at bugs.digium.com]

A NOTE has been added to this issue. 
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http://bugs.digium.com/view.php?id=10530 
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Reported By:                xmarksthespot
Assigned To:                
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Project:                    Asterisk
Issue ID:                   10530
Category:                   Channels/chan_iax2
Reproducibility:            always
Severity:                   minor
Priority:                   normal
Status:                     new
Asterisk Version:            SVN 
SVN Branch (only for SVN checkouts, not tarball releases):  1.4  
SVN Revision (number only!): 79747 
Disclaimer on File?:        N/A 
Request Review:              
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Date Submitted:             08-22-2007 11:30 CDT
Last Modified:              10-03-2007 13:27 CDT
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Summary:                    DTMFs passing only in part between two asterisk
machines with an IAX2 connection
Description: 
Note: I am unable to pinpoint the exact location of the problem, be it SIP,
IAX or something else. To the best of my knowledge the fault lies with IAX,
but I may be incorrect.

Here are the network setups:
Setup 1: PSTN <-- PRI --> Asterisk1 <-- IAX2 --> MyPBX <-- SIP -->
MyPolycomPhone
Setup 2: PSTN <-- Analog Lines --> OtherPBX <-- SIP --> MyPolycomPhone

The network setup between all these setups is always the same, only a
single switch separates these machines.

When a call is initiated (I usually test with the call being initiated
from MyPolycomPhone out to the PSTN), the passing of the DTMFs becomes very
incomplete, even if seems to depend on the length of the keypresses.

For example, I use MyPolycomPhone and call out to one of my Dialogic
machines. The Dialogic machine answers me and awaits that I enter
something. If I dial very fast, usually a sequence like 1234567890, only a
very small part of the dtmfs actually make it through. The others seem to
be simply missing. It's as if they never made it, or were never pressed, at
least it seems that way to the Asterisk1 machine.

However, the local dtmf detection on MyPBX is flawless, which leads me to
believe it might be some issue with IAX2 instead of SIP. I made an
extensions that uses the Read() command and waits for the user to enter 10
digits. Everytime I tried it, as fast as I could, it worked flawlessly.

On the PSTN, it is totally the opposite. The majority of the DTMFs do not
pass. It usually seems to depend on the length of the keypresses. If the
keypresses are done in a slow, controlled manner they pass. If I use "setup
2", knowing that the OtherPBX is an Asterisk 1.2 machine with analog lines,
the same test, the DTMFs on the PSTN work flawlessly, just like locally on
"setup 1". 

Then I decided to hook up OtherPBX in the same way as MyPBX is hooked,
that is to create setup 3, which would be like so:

Setup 3: PSTN <-- PRI --> Asterisk1 <-- IAX2 --> OtherPBX <-- SIP -->
MyPolycomPhone

This Setup 3 works flawlessly. I haven't submitted any debug of it,
because everything is dandy.

So there's something weird going on when MyPBX (SVN Branch 1.4 rev 79747)
talks DTMFs to Asterisk1 (1.4.6).
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---------------------------------------------------------------------- 
 pj - 10-03-07 13:27  
---------------------------------------------------------------------- 
I have suspicion, that this issues appears after vldtmf (variable lenght
dtmf) was added to asterisk, from this point, I can also say, that dtmf is
not 100% realiable, mainly in cases, sending digits quickly, without
pauses.
my setup:
skinny-->asteriskA--iax--->asteriskB(dejitter)--->asteriskA-(Waitexten/IVR
here) 

Issue History 
Date Modified   Username       Field                    Change               
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10-03-07 13:27  pj             Note Added: 0071406                          
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