I still don't see a reason to use it.  If you want immediate information
about phones even in the event of a catastrophic failure, bypass the
cache altogether (that's what we do) and have it do a lookup every time.
Also, set your lookup time to an acceptable value in the event that the
primary DUNDi servers don't find the phone.  I think ours is extremely
low since we've only got a small number of servers.

>From the stats that I got from JR's talk on DUNDi at Astricon, seems to
me the overhead of doing the DUNDi lookups are almost nil, so personally
I think caching is pointless in a highly available environment.

On Thu, 2006-11-09 at 12:19 -0700, Douglas Garstang wrote:
> I also just realised a distinct advantage of the precache model.
> 
> Lets say you have a central DUNDi cache server. He has in his cache the 
> knowledge that appearance 2944093 is registered to pbx1 for the next hour. If 
> pbx1 where to crash, then for the next hour, calls to 2944093 would fail. 
> 
> However, in the precache model, when the phone registers to an Asterisk box, 
> the Asterisk box immediately precaches the information to the central DUNDi 
> server, who maintains this information until it's updated. If pbx1 where to 
> crash, and the phone failed over to pbx2, pbx2 would then send updated 
> registration information to the DUNDi precache server, and thus calls would 
> not fail for an hour.
> 
> Douglas.
> 
> > -----Original Message-----
> > From: Aaron Daniel [mailto:[EMAIL PROTECTED]
> > Sent: Thursday, November 09, 2006 11:04 AM
> > To: Asterisk Users Mailing List - Non-Commercial Discussion
> > Subject: RE: [asterisk-users] DUNDi precache
> > 
> > 
> > Why would you want to do that?  Defeats the purpose of *having* the
> > DUNDi protocol.  Why not just program the extensions in at regular
> > intervals or something?
> > 
> > On Thu, 2006-11-09 at 10:16 -0700, Douglas Garstang wrote:
> > > Aaron.
> > > 
> > > Thanks. JR sent me that article before it was published. 
> > He's not precaching registrations. He's doing something 
> > different. In his configuration, when a registration server 
> > gets a request for the location of a phone, it queries the 
> > DUNDi Lookup server, which in turn queries the other 
> > registration servers on it's behalf. It doesn't actually 
> > cache the registrations itself. 
> > > 
> > > According to what Mark Spencer wrote, it should be possible 
> > for this DUNDi Lookup server to hold, or store (ie cache) 
> > -all- phone registration info so that it doesn't have to 
> > query the other registration servers. 
> > > 
> > > Doug. 
> > > 
> > > > -----Original Message-----
> > > > From: Aaron Daniel [mailto:[EMAIL PROTECTED]
> > > > Sent: Thursday, November 09, 2006 9:55 AM
> > > > To: Asterisk Users Mailing List - Non-Commercial Discussion
> > > > Subject: Re: [asterisk-users] DUNDi precache
> > > > 
> > > > 
> > > > Doug,
> > > > 
> > > > This may help you out a little.  It's a whitepaper that JR 
> > > > wrote on how
> > > > to get a DUNDi cluster working with two redundant primary 
> > servers that
> > > > handle all the DUNDi legwork.  Read through it, you might get some
> > > > information you can use out of it.
> > > > 
> > > > http://txaug.net/storage/users/3/3/images/17/Using%20DUNDi%20w
> > > ith%20a%20Cluster%20of%20Asterisk%20Servers.pdf
> > > 
> > > On Thu, 2006-11-09 at 08:36 -0700, Douglas Garstang wrote:
> > > > Does anyone have any information on how to use DUNDi precaching?
> > > > 
> > > > Mark Spencer made a post 2 years ago where he hinted it 
> > may be possible to configure DUNDi such that you could 
> > centralise your DUNDi registration info by using precaching, 
> > instead of having each DUNDi peer meshed with every other one...
> > > > 
> > > > http://lists.digium.com/pipermail/dundi/2004-October/000189.html
> > > > 
> > > > However, it seems that no documentation exists for this 
> > in the known universe.
> > > > 
> > > > Doug.
> > > > _______________________________________________
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> > 
> > -- 
> > Aaron Daniel
> > Computer Systems Technician
> > Sam Houston State University
> > [EMAIL PROTECTED]
> > (936) 294-4198
> > 
> > _______________________________________________
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-- 
Aaron Daniel
Computer Systems Technician
Sam Houston State University
[EMAIL PROTECTED]
(936) 294-4198

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