asterisk users - Dec 2003 - Multiple Asterisk servers sharing/propagating registry ?

Dear all,

I'd like to know if there is a way for multiple asterisk servers to
share a common SIP and/or IAX registry.

The setup I imagine would be something like :
- several asterisk servers called sip1.isp.com, sip2.isp.com, ...
- a DNS alias sip.isp.com pointing to all the addresses (thus
  providing a round robin resolution on each server)
- each SIP client would register with sip.isp.com (thus ending on a
  random asterisk servers)
- but after that, all the servers would be "aware" of the
  registration. Thus any asterisk server would know how to route a
  call to SIP/<some registered user>

Same thing for IAX peers.

Of course, setting up various IAX links between each server is no
problem (with registration cascading, for instance).

Is such a setup common, if at all possible ?

--
Nicolas Bougues
Axialys Interactive

At 22:47 8-12-2003 +0100, you wrote:
>The setup I imagine would be something like :
>- several asterisk servers called sip1.isp.com, sip2.isp.com, ...
>- a DNS alias sip.isp.com pointing to all the addresses (thus
>   providing a round robin resolution on each server)
>- each SIP client would register with sip.isp.com (thus ending on a
>   random asterisk servers)
>- but after that, all the servers would be "aware" of the
>   registration. Thus any asterisk server would know how to route a
>   call to SIP/<some registered user>
>
>Same thing for IAX peers.
>
>Of course, setting up various IAX links between each server is no
>problem (with registration cascading, for instance).
Registration cascading is not possible (I think) but could it be solved 
with a shared dial route:

Instead of DIAL(IAX/sip.isp.com) could you not 
DIAL(IAX/sip1.isp.com&IAX/sip2.isp.com&IAX/sip3.isp.com) to reach a
similar
effect ? (or chain them in different lines so it tries to reach the first 
one, then the second one if it fails, and the third if that fails.

Florian

Nicolas Bougues wrote:
> On Tue, Dec 09, 2003 at 08:02:18AM -0600, Mark Spencer wrote:
> 
>>I suppose trunk groups on SIP would be interesting.
>>
> 
> 
> As I understand, trunking in IAX is meant to transport voice packets
> from several calls between two hosts in the same lower layer packet.
> 
> Are there registration features related to trunking ?
> 
> In fact, what would be very nice to have would be some kind of
> trunking with registry/dialplans automatic exchange, so that one can
> easily setup a larger virtual PBX, that would server both capacity and
> redundancy requirements.
> 
> I keep on thinking :)
> 
...and I recommend reading :-)
http://www.voip-info.org/wiki-Asterisk+-+dual+servers

/O

----- Original Message -----
From: "Florian Overkamp" <florian@obsimref.com>
To: <asterisk-users@lists.digium.com>
Sent: Tuesday, December 09, 2003 2:28 AM
Subject: Re: [Asterisk-Users] Multiple Asterisk servers sharing/propagating
registry ?

> At 22:47 8-12-2003 +0100, you wrote:
<snip>
> Instead of DIAL(IAX/sip.isp.com) could you not
> DIAL(IAX/sip1.isp.com&IAX/sip2.isp.com&IAX/sip3.isp.com) to reach a
similar
> effect ? (or chain them in different lines so it tries to reach the first
> one, then the second one if it fails, and the third if that fails.
>
> Florian
Can someone show me Dial lines that would be "chained"? I have had
trouble
making it work like I think they should...

-----
Andrew Thompson http://aktzero.com/
Your eyes are weary from staring at the CRT. You feel sleepy. Notice how
restful it is to watch the cursor blink. Close your eyes. The opinions
stated above are yours. You cannot imagine why you ever felt otherwise.

Hi Andrew,

Citeren Andrew Thompson
<asteriskuser@aktzero.com>:
> > Instead of DIAL(IAX/sip.isp.com) could you not
> > DIAL(IAX/sip1.isp.com&IAX/sip2.isp.com&IAX/sip3.isp.com) to
reach a
> similar
> > effect ? (or chain them in different lines so it tries to reach the
first
> > one, then the second one if it fails, and the third if that fails.
> 
> Can someone show me Dial lines that would be "chained"? I have
had trouble
> making it work like I think they should...
I use it like this:

[macro-dial]
exten=s,1,Dial(IAX2/${ARG1}@${ARG1},30,r)
exten=s,2,Dial(IAX/${ARG1}@${ARG1},30,r)
exten=s,3,Dial(SIP/${ARG1}@${ARG1},30,r)

exten=s,4,SetLanguage(nl)
exten=s,5,Answer
exten=s,6,Background(vm-nobodyavail)
exten=s,7,Hangup

exten=s,102,Goto(2)
exten=s,103,Goto(3)
exten=s,104,Goto(4)


-- 
Best regards,
Florian Overkamp

> I'd like to know if there is a way for multiple asterisk servers to
> share a common SIP and/or IAX registry.
> The setup I imagine would be something like :
> - several asterisk servers called sip1.isp.com, sip2.isp.com, ...
> - a DNS alias sip.isp.com pointing to all the addresses (thus
>   providing a round robin resolution on each server)
> - each SIP client would register with sip.isp.com (thus ending on a
>   random asterisk servers)
> - but after that, all the servers would be "aware" of the
>   registration. Thus any asterisk server would know how to route a
>   call to SIP/<some registered user>
I would like to know how to do this as well, but for different reasons: 
mobile users.  If I'm in the office my SIP phone registers with the local * 
box, or at my house wiht my * box, and so on and so forth, so my extension 
moves with me.  If I'm not anywhere near a * box the SIP registration 
eventually dies and since there's no SIP registration it calls my cell 
phone...  kind of like a universal extension type of thing.

I know I can dial all of them with one extension and whichever picks up 
picks up but that seems a little ... hokey.  I can't think of a better way 
to do it short of being able to propagate registrations across * boxes.

Regards,
Andrew