asterisk users - Dec 2005 - Mechanisms for Implementing a Common Contact Database

Well, I feel like I'm flogging a dead horse here, but I figured I'd at
least do my bit and throw some ideas out there about how to implement a common
contact database now that it's been confirmed that Realtime can't do
this.
 
1. A script that runs on one or more boxes in the Asterisk farm and at (very)
regular intervals replicates the differences in the /var/lib/asterisk/astdb
file, such that each Asterisk box always knows wheve every phone is and can
therefore terminate calls to all phones. Wouldn't be too hard to write.
Major con is that Asterisk has to be reloaded to see the new astdb file and I
don't think I'd want to be performing reloads on a production system
every say, 10s or so.
 
2. It'd be cool if the regcontext command actually did something.
There's a myth out there that it does something like execute a command upon
registration. Even the O'Reilly "The Future of Telephony" seems to
think this. After reading some posts in the developer discussion I can say it
doesn't. It would be great though, if upon registration from a phone,
Asterisk could perform some action, say for example copying the registration to
another Asterisk system.
 
3. Phones register to OpenSER. Openser upon a REGISTER forwards the packets to N
number of Asterisk boxes who then get a registration for the user. I've
tested this and it works. Each Asterisk system then knows where every phone is
and can terminate calls to any phone. However, I'm no SER expert (is anyone)
and when the phones start sending SUBSCRIBE and receiving NOTIFY messages, with
SER in the middle, it all gets very ugly.
 
4. Could all Asterisk systems be given access to a common file store? NFS or a
SAN maybe? Does anyone know what what happen if multiple Asterisk boxes tried to
use/write to the same astdb file? Anyone? Anyone?
 
5. DUNDi? Couldn't get it to work. Spent weeks on it and then realised that
all the examples have RSA keys in what I thought was sip.conf. The sip.conf file
doesn't support RSA keys.
 
I really hopes someone takes the time to reply to this message. Surely I'm
not the only person in the universe who's trying to implement a HA Asterisk
system. I would think it would be for the good of all to come up with some sort
of a solution.
 
It amazes me that when I search for Asterisk redundancy on google, I keep coming
up with my own posts!
 
I feel like I have been beating my head against a wall. Every time I think
I'm close to coming up with some sort of hack or solution, some other
limitation gets in the way and stops it dead in it's tracks.

Hi Douglas!
> 2. It'd be cool if the regcontext command actually did something.
> There's a myth out there that it does something like execute a command
> upon registration. Even the O'Reilly "The Future of
Telephony" seems
> to think this. After reading some posts in the developer discussion I
> can say it doesn't. It would be great though, if upon registration
> from a phone, Asterisk could perform some action, say for example
> copying the registration to another Asterisk system. 
I have some more reading for that might help you in your quest:

manager API & peer registration:

http://www.voip-
info.org/wiki/index.php?page=Asterisk+Manager+API+Action+Events
http://www.asteriskjava.org/latest/apidocs/net/sf/asterisk/manager/event/R
egistryEvent.html

hint and metermaid (not exactly what you are looking for, but still):
http://bugs.digium.com/view.php?id=5779

Cheers, Philipp