[jdev] Discovering the Federation.

Justin Karneges justin-keyword-jabber.093179 at affinix.com
Wed Aug 30 00:49:04 CDT 2006

On Tuesday 29 August 2006 21:07, Daniel Noll wrote:
> > I just got an idea: Why not use DHCP for this? It can already be used to
> > discover your default IRC server (8.19 in RFC-2132), so why not your
> > default XMPP server?
> We already have another way to do it too, DNS Service Discovery.

That's true.  For those not in the know, DNS-SD lets you query a domain for a 
list of services.  DNS-SD is commonly used in conjunction with Multicast DNS 
to scan the local network for services, but DNS-SD can also be used with 
regular DNS.

DNS-SD is essentially one more layer above SRV.  Instead of asking for "the 
Jabber server at example.com" (with SRV), you ask for "Jabber servers at 
example.com" (with a specially encoded PTR query).  This results in a list of 
friendly, user-readable names (not hostnames!).  Then you can SRV resolve any 
of the names.  The idea is that a user can browse his domain, see a list of 
named services, and then pick one.  For example, browsing a domain for ftp 
servers might result in "Joe's Shared FTP" and "Mike's Vault".

However, this is really only useful if you plan to have more than one Jabber 
server in a given domain, and you want a friendly way for the user to pick 
the right one.  For Hal's purposes, SRV alone is probably enough.


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