[asterisk-users] PRI: sometimes Asterisk drop calls

Steve Davies davies147 at gmail.com
Wed Sep 13 02:15:32 MST 2006

On 9/12/06, Giorgio Incantalupo <gincantalupo at fgasoftware.com> wrote:
> I'm interested to understand why I many messages like:
> WARNING[21314] chan_zap.c: Ring requested on channel 0/1 already in use
> on span 1.  Hanging up owner
> How can a channel be already in use??? That means the channel is
> busy...if it is so then it is all right...but maybe that shouldn't be a
> warning but a notice or something else...should it?

What this means is that a call has arrived from your Telco on a Zap
channel. Asterisk THINKS that this channel is already in use - In my
case, asterisk is wrong. Sadly, asterisk hangs up the new call (so
no-one can call you anymore!) and does not have an option to clean up
the call data to show the channel as free. Outbound calls are fine,
but will never be placed on this "hung" channel.

IMHO, 99% of the time, if the telco says a channel is free, they know best!!!

As per my other email, I see this problem on one site. Sadly I have
not been able to identify where it comes from (although I suspect
broken SIP clients upsetting Asterisk)

What versions of zaptel/asterisk do you use? What hardware, and what
phone devices? Perhaps people with this problem have something in

To start the ball rolling:
  Software: Zaptel 1.0.9, Asterisk 1.0.9, BRIstuff-0.2.0, wanpipe-2.3.2
  PRI interface: Sangoma A101U (UK E1)
  Phones on sites with NO problems: snom, elmeg, Aastra, Linksys/Sipura
  Phones on problem site: Hitachi WIP3000, Zyxel F1000 (?)


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