asterisk users - Dec 2009 - Asterisk ZAP/DAHDI reads phantom digit on overlap PRI

Hi,

I've noticed that a small but meaningful quota of calls from my Alcatel PBX
to Asterisk are failing.

This does not always happen and it is not easily reproducible but on high
traffic I do get a large number of cases.

Example: Alcatel PBX extension 7085 calls Asterisk PBX extension 6145 over a PRI
E1 link.

I see this in the Asterisk log:

Dec 14 14:10:31 VERBOSE[11378] logger.c:     -- Accepting overlap call from
'7085' to '6145' on channel 1/31, span 1
Dec 14 14:10:31 VERBOSE[5558] logger.c:     -- Starting simple switch on
'Zap/31-1'
Dec 14 14:10:32 DEBUG[5558] chan_zap.c: DTMF digit: 5 on Zap/31-1
Dec 14 14:10:40 DEBUG[5558] chan_zap.c: No such possible extension
'61455' in context 'from-alcatel'

Obviously, it's failing because Asterisk is trying to match
destination+extra DTMF digit (ie. 6145+5).

However, noone ever dialed that extra digit! So how did it get there?

I guess I could disable "overlap" in Asterisk but that isn't the
right way to go.

What else can I do (where else can I look) to solve this issue?

Thanks,

Vieri

On Mon, Dec 14, 2009 at 05:32:21AM -0800, Vieri wrote:
> Hi,
> 
> I've noticed that a small but meaningful quota of calls from my Alcatel
PBX to Asterisk are failing.
> 
> This does not always happen and it is not easily reproducible but on high
traffic I do get a large number of cases.
> 
> Example: Alcatel PBX extension 7085 calls Asterisk PBX extension 6145 over
a PRI E1 link.
> 
> I see this in the Asterisk log:
> 
> Dec 14 14:10:31 VERBOSE[11378] logger.c:     -- Accepting overlap call from
'7085' to '6145' on channel 1/31, span 1
> Dec 14 14:10:31 VERBOSE[5558] logger.c:     -- Starting simple switch on
'Zap/31-1'
> Dec 14 14:10:32 DEBUG[5558] chan_zap.c: DTMF digit: 5 on Zap/31-1
> Dec 14 14:10:40 DEBUG[5558] chan_zap.c: No such possible extension
'61455' in context 'from-alcatel'
> 
> Obviously, it's failing because Asterisk is trying to match
destination+extra DTMF digit (ie. 6145+5).
> 
> However, noone ever dialed that extra digit! So how did it get there?
> 
> I guess I could disable "overlap" in Asterisk but that isn't
the right way to go.
> 
> What else can I do (where else can I look) to solve this issue?
Please provide trace from 'pri debug' .

-- 
               Tzafrir Cohen
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