[asterisk-users] ISDN PRIs and taking a server down for maintenance - blocking issue

[Andrew Smith]

Hi Tim,

Imagine the scenario where we had 10x Asterisk servers, with calls
presenting sequentially starting from the first server, then server two,
etc.
 
If we took down the first server for maintenance with 'asterisk -rx stop
gracefully' we then will block all incoming calls to all servers as our
telco will simply relay the BUSY back to the caller. If there are a number
of calls on the first server that continue for another 20 minutes, then all
inbounds are blocked for that period of time.
 
We are finding at present we have to look at the calls on the server and
make a decision if we are busy to simply reboot the server and hence lose
calls. Not ideal but then we don't end up blocking our inbounds.

What I was hoping to do was find a way to cause the telco to present the
call to the next ISDN30 and therefore would allow us to cleanly take down an
Asterisk server for maintenance without causing this issue. In a sense to
put the ISDN30 into alarm mode while still continuing the active calls.
 
Do you know if this is at all possible, even if we considered patching
zaptel to add this functionality or does the telco rely on the entire PRI
being in alarm before it presents the call to the next ISDN30 ? This would
allow us to run maintenance on our servers during busy periods without
causing disruption, and would be an excellent feature.

Many thanks,
Andrew

  _____  

From: asterisk-users-bounces at lists.digium.com
[mailto:asterisk-users-bounces at lists.digium.com] On Behalf Of Tim Nelson
Sent: 13 February 2008 18:12
To: Asterisk Users Mailing List - Non-Commercial Discussion
Cc: asterisk-users at lists.digium.com
Subject: Re: [asterisk-users] ISDN PRIs and taking a server down for
maintenance - blocking issue


Even if * is shutdown, zaptel is still running and your ISDN channels are
still technically up. Shutting down zaptel should close the channels and put
those circuits into alarm mode.

Tim Nelson
Systems/Network Support
Rockbochs Inc.
(218)727-4332

----- Original Message -----
From: "Andrew Smith" <andrews at meadeplc.com>
To: asterisk-users at lists.digium.com
Sent: Wednesday, February 13, 2008 12:03:51 PM (GMT-0600) America/Chicago
Subject: [asterisk-users] ISDN PRIs and taking a server down for maintenance
- blocking issue


Hi there,
 
I currently have multiple Asterisk servers using Sangoma A104d Quad ISDN
E1s.

Basically our telco is presenting calls in order of the ISDNs on our
servers.
 
SERVER1=1,2,3,4
SERVER2=5,6,7,8
 
We have redundancy in that if SERVER1 is shutdown then each ISDN PRI is in
alarm and the calls will then presented to PRIs 5,6,7,8 on SERVER2.

If I have to take SERVER1 offline for maintenance (asterisk -rx shutdown
gracefully) any incoming calls receive a BUSY tone.

What I would like to know is if there is anyway to get around this and not
send a BUSY back to our callers and somehow allow our telco to present calls
immediately to SERVER2.

Anyone have any ideas or are we stuck with this behaviour until the calls
drop to 0 and Asterisk shuts down ?

Thanks,
Andrew
 
 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.digium.com/pipermail/asterisk-users/attachments/20080214/8f93b015/attachment.htm