[Asterisk-Users] Update to the latest zaptel driver - Congestion gone, but scary write errors replaced it

[Keiron Liddle]

Hi Edwin,

We appear to be having the exact same problems as you are, congestion 
happens at certain times of the day, we get constant messages about 
hanging up on bad channel, all calls are moved to a different channel by 
the exchange, often get can't fix up channel because already in use, 
aapt say there is nothing wrong at their end etc.

Firstly the congestion is actually real, what is happening is that 
asterisk is not releasing a line properly and so when the exchange gets 
a busy signal back for over a few minutes then they permanently block 
the line until a hard reset is done on the PRI. So that asterisk thinks 
the line is fine but it is blocked, so when a call is made on the line 
by asterisk it immediately comes back as congested. The problem seems to 
occur when there are lots of calls made on the line in succession, 
possibly without the call being answered. It might be that it needs to 
do a restart on the channel but doesn't get a chance.
When I tried to use a more recent zaptel it worked really badly and kept 
dropping all calls when it went above about 20 calls at a time.

Keiron

Edwin Groothuis wrote:

>Hi,
>
>Yesterday I updated asterisk to the latest zaptel driver and today
>my congestion problems are gone... (see
>http://bugs.digium.com/view.php?id=6509), only to be replaced by:
>
>Feb 17 10:02:37 DEBUG[19225] chan_zap.c: Write returned -1 (Resource temporarily unavailable) on channel 26
>Feb 17 10:03:08 DEBUG[19274] chan_zap.c: Write returned -1 (Resource temporarily unavailable) on channel 216
>Feb 17 10:03:34 DEBUG[19334] chan_zap.c: Write returned -1 (Resource temporarily unavailable) on channel 2
>
>That is on zap-channels. What is going on?
>
>Edwin
>  
>