This exact problem is solved by the short cache time, this is one of the reasons behind the low cache time in the white paper by JR.Your example is correct also, but your are expecting pbx2 to "push" the information to the server whereas JR has the central server pull the information. Both work, but cache is automatic and the traffic is as needed not per registration.
<br><br>As to your comments about a central cache server, I make use of it in our deployment over 8 sites connected via a WAN. The central server model cuts down the complexity of the configurations on remote sites. I am working on putting a second cache server in a remote site for redundancy. Again, even over the wan links the lookup time from server A to the central to server B and back is 70 to 160 ms, plenty fast to not cause a pause in the dialing of a call.
<br><br><div><span class="gmail_quote">On 11/9/06, <b class="gmail_sendername">Douglas Garstang</b> <<a href="mailto:dgarstang@oneeighty.com">dgarstang@oneeighty.com</a>> wrote:</span><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
I also just realised a distinct advantage of the precache model.<br><br>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.
<br><br>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.
<br><br>Douglas.<br><br>> -----Original Message-----<br>> From: Aaron Daniel [mailto:<a href="mailto:amdtech@shsu.edu">amdtech@shsu.edu</a>]<br>> Sent: Thursday, November 09, 2006 11:04 AM<br>> To: Asterisk Users Mailing List - Non-Commercial Discussion
<br>> Subject: RE: [asterisk-users] DUNDi precache<br>><br>><br>> Why would you want to do that? Defeats the purpose of *having* the<br>> DUNDi protocol. Why not just program the extensions in at regular<br>
> intervals or something?<br>><br>> On Thu, 2006-11-09 at 10:16 -0700, Douglas Garstang wrote:<br>> > Aaron.<br>> ><br>> > Thanks. JR sent me that article before it was published.<br>> He's not precaching registrations. He's doing something
<br>> different. In his configuration, when a registration server<br>> gets a request for the location of a phone, it queries the<br>> DUNDi Lookup server, which in turn queries the other<br>> registration servers on it's behalf. It doesn't actually
<br>> cache the registrations itself.<br>> ><br>> > According to what Mark Spencer wrote, it should be possible<br>> for this DUNDi Lookup server to hold, or store (ie cache)<br>> -all- phone registration info so that it doesn't have to
<br>> query the other registration servers.<br>> ><br>> > Doug.<br>> ><br>> > > -----Original Message-----<br>> > > From: Aaron Daniel [mailto:<a href="mailto:amdtech@shsu.edu">amdtech@shsu.edu
</a>]<br>> > > Sent: Thursday, November 09, 2006 9:55 AM<br>> > > To: Asterisk Users Mailing List - Non-Commercial Discussion<br>> > > Subject: Re: [asterisk-users] DUNDi precache<br>> > >
<br>> > ><br>> > > Doug,<br>> > ><br>> > > This may help you out a little. It's a whitepaper that JR<br>> > > wrote on how<br>> > > to get a DUNDi cluster working with two redundant primary
<br>> servers that<br>> > > handle all the DUNDi legwork. Read through it, you might get some<br>> > > information you can use out of it.<br>> > ><br>> > > <a href="http://txaug.net/storage/users/3/3/images/17/Using%20DUNDi%20w">
http://txaug.net/storage/users/3/3/images/17/Using%20DUNDi%20w</a><br>> > ith%20a%20Cluster%20of%20Asterisk%20Servers.pdf<br>> ><br>> > On Thu, 2006-11-09 at 08:36 -0700, Douglas Garstang wrote:<br>> > > Does anyone have any information on how to use DUNDi precaching?
<br>> > ><br>> > > Mark Spencer made a post 2 years ago where he hinted it<br>> may be possible to configure DUNDi such that you could<br>> centralise your DUNDi registration info by using precaching,
<br>> instead of having each DUNDi peer meshed with every other one...<br>> > ><br>> > > <a href="http://lists.digium.com/pipermail/dundi/2004-October/000189.html">http://lists.digium.com/pipermail/dundi/2004-October/000189.html
</a><br>> > ><br>> > > However, it seems that no documentation exists for this<br>> in the known universe.<br>> > ><br>> > > Doug.<br>> > > _______________________________________________
<br>> > > --Bandwidth and Colocation provided by <a href="http://Easynews.com">Easynews.com</a> --<br>> > ><br>> > > asterisk-users mailing list<br>> > > To UNSUBSCRIBE or update options visit:
<br>> > > <a href="http://lists.digium.com/mailman/listinfo/asterisk-users">http://lists.digium.com/mailman/listinfo/asterisk-users</a><br>><br>> --<br>> Aaron Daniel<br>> Computer Systems Technician
<br>> Sam Houston State University<br>> <a href="mailto:amdtech@shsu.edu">amdtech@shsu.edu</a><br>> (936) 294-4198<br>><br>> _______________________________________________<br>> --Bandwidth and Colocation provided by
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<br> <a href="http://lists.digium.com/mailman/listinfo/asterisk-users">http://lists.digium.com/mailman/listinfo/asterisk-users</a><br></blockquote></div><br><br clear="all"><br>-- <br>Bruce<br>Nortex Networks