[Asterisk-biz] Clustering Solutions for Asterisk

[Paul]

I am working on a similar problem and have some ideas for you.  First I'm
using two servers with a T1 card in each.  I have two companies currently in
the same location so the IP range can be in the same subnet without worrying
about SER or the like.

In order for two companies to be on their own server yet be redundant to
each other I have devised a calling plan where both extensions are dialed to
reach the user (and both extensions have voicemail).  As an example,
operator for company one is extension 200 as well as 200 on the backup
(second company) server and the extensions file dials both (using IAX to
link servers). So regardless of phone registration, the call can be
answered.

Each server has the same configuration (a complete mirror copy) allowing the
dial out to use the PRI line that is active (there is only one - again IAX
link)

Since I have not found any T1 cards that offer failover yet, the customer
must move the T1 cable.  I was thinking about using the led power on the T1
card (when polarity reverses to red) and wire it to an optoisolator, time
delay and old fashion relay to move the T1 to the second server if I cant
find an external T1 failover switch for a good price.

I did speak to Sangoma Technologies about adding this feature to their card
but they have not done so yet.  

I have been playing with this for a month now and some of the problems I'm
facing are the refusal of SIP 7.5 on Cisco's 7960s to use the emergency
proxy when the primary is not responding.

Some other minor problems are how to move the voice mail back to the correct
servers as well as the call reporting.  I'm approaching this from two
avenues -
1 - Internal cron jobs looking at each others servers to pull the data back 
2 - A separate Win XP station using a custom VS net program into the mysql
databases of each server as well as possibly being the trigger for the T1
failover.

I have not finished this yet, but if anyone has any ideas or has tried what
I am trying please let me know also.  Also - interesting thought about the
linking of servers, does the IAX link cause a transcode on inbound and
outbound (extension to extension as well as extension to T1 BETWEEEN BOXES)?
Should I link them through SIP which is used by all phones?

I'm just trying to use the mirror approach which is great for SMB's - my
market.

Paul Norris
(631) 878-6438
Silicon Valley Products
E. Moriches, NY







>Has anyone real experiences with clustering for Asterisk ?

>I already did some googling, and also look at wi-ki for solutions for High
>Avaiability, but I did not find enough info to aply a solution for my
>customer.

>He wants a cluster, and if possible, to have their staff load balanced to
>two asterisk. When one of them crash or does not works correctly, the other
>one should make his job on a transparent work to the users...

>So, I prefer an active-active cluster, but if that is impossible to cover,
>it is Ok to have an active-passive cluster.

>It would be nice if also it could cover the following

>- Customer has only on PRI (E1) line... Is there any way for both asterisk
>to use the same circuit ?

>Also, for small installations (to 8 extensions) I would need a solution for
>the main operator phone to remain active if Asterisk goes down. I mind, if
>PBX does not work, the external line should at least get connected dirctly
>to the phone and allow them to receive calls until situation is solved. Any
>idea on this ?