[asterisk-users] Unable to create channel of type 'DAHDI' (cause 0- Unknown)

[Karl Fife]

I have had the exact same problem for over a year on my server sporting the 
TDM800 but NOT on my server with the TE212P.  Both servers run the same 
version of Linux, Asterisk and DHADI.

The problem has remained consistent through all versions of DAHDI 2.0.x 
through 2.2.0.2, and every version of Asterisk which I have I've tried which
includes various iterations of 1.6.0, 1.6.1, and 1.6.2.  Currently 1.2.6.1. 
Surprisingly I also observe that I can even compile & install NEW versions 
of Asterisk and/or DAHDI, and NOT observe the bug provided that I do NOT 
bounce the server.

A developer (not an asterisk developer) named Jim Duda posted this issue to 
the list back in October of 08.   (Asterisk 1.6.0-beta9 & DAHDI 2.0.x 
originally for him).  After what he described as considerable effort he 
found that by changing one line in chan_dahdi.c the issue appeared to be 
resolved (below).  His simple patch (below) has works (for me too) as a 
stop-gap.

I posted this the DEV list back January of 09, and the issue was reopened 
and then closed as 'fixed' .  It would appear the issue needs to be 
re-reopened, as it's now appearing less specific to my hardware or 
configuration.

https://issues.asterisk.org/view.php?id=13786
Duplicate issue to 13927

If I do not patch chan_dahdi (below), this is what I (still) observe:
ONLY after a system reboot, any attempt(s) to dial from a device attached to 
an FXS port on my TDM800P, result in the following error :

WARNING[2975]: app_dial.c:1502 dial_exec_full: Unable to create channel of 
type 'DAHDI' (cause 0 - Unknown)
  == Everyone is busy/congested at this time (1:0/0/1)

BUT after the first INBOUND call to any FXO port on the device, the FXS port 
works normally until the next reboot.

(Asterisk 1.6.2.1 & DAHDI 2.2.0.2 (& earlier ) Centos 2.6.18-164.11.1.el5 #1 
SMP Wed Jan 20 07:39:04 EST 2010 i686 i686 i386 GNU/Linux

Does anyone else observe this?  Could it be specific to certain 
(mis)configurations?  It's possible that others have the issue but do not 
know it.  With any inbound call volume it may be nearly transparent :-)

-Karl

JIM's ONE-LINE FIX ----
On line 8730 (I think it's still on this line) of chan_dahdi.c
replace a "return 0"  with return "1".

if (par.rxisoffhook)
return 1;
else
- return 0;
+ return 1;



----- Original Message ----- 
From: "Walter Arguello" <walter_arguello at yahoo.com>
To: <asterisk-users at lists.digium.com>
Sent: Thursday, January 28, 2010 6:15 PM
Subject: [asterisk-users] Unable to create channel of type 'DAHDI' (cause 0-
Unknown)


> Hi,
>
> I have a tdm22b (2 fxs / 2 fxo)
>
> When Asterisk is just started, outbound calls routing to fxo port, do not
> working with error:
>
> Unable to create channel of type 'DAHDI' (cause 0 - Unknown)
>
> Inbound calls to fxo port work fine.
>
> After first inbound call, the outbound calls starts working.
>
> CentOS 5.4
> asterisk 1.6.0.21-1
> dahdi 2.2.1.-1
>
> Can anybody help me to identify what is the possible cause of problem?
>
> Thanks,
>
> Walter.
>
>
>
>
>
> -- 
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