[Jingle] XEP-0176 - how to find STUN/TURN servers

[Marcus Lundblad]

tis 2009-04-07 klockan 19:05 -0600 skrev Peter Saint-Andre:
> On 4/7/09 6:38 PM, Justin Karneges wrote:
> > Section 9 mentions STUN/TURN, but does not suggest how a client may discover 
> > these services through the XMPP server.  In particular, TURN servers may 
> > require credentials and the client will need to know what they are.
> 
> There are defined methods for discovering STUN/TURN servers using DNS
> SRV records.
> 
> > Even XEP-0065 has a way to locate a relay service, through disco.  
> 
> That's because a SOCKS5 Bytestreams proxy communicates over XMPP.
> 
> > I think we 
> > need a similar approach in XEP-0176 before we can consider it ready.
> 
> Yes, I've been thinking about that. The method we've defined so far is
> XEP-0215 (External Service Discovery), which is semantically the same as
> the method used in Google Talk (jingle-info or whatever they call it).
> An alternative approach would be to XMPP-enable a TURN server so that
> you could communicate with it over XMPP, just as you do for a SOCKS5
> Bytestreams proxy. However, that would require a customized TURN server.
> But I suppose you could argue that XEP-0215 would require a customized
> TURN server, too. I think this is an open issue -- not for XEP-0176 but
> for Jingle in general.

The way it works using Google's "jingle-info" is that you issue a
jingle-info get request. In response you get a list of STUN servers (IP
and port) and a relay discovery address + a relay token.
The client then issues an HTTP request to that URL setting the token in
a content header. The HTTP response now contains a list of value-pairs
for hosts, ports and so on.

I guess we'd need some way for XEP-0215 to enable communicating with a
TURN server. Though that would probably require a customised TURN
server. I'm not sure quite how we could implement something like this
without requiring a custom TURN server, which would sure be a nice
thing.

//Marcus 

> 
> Peter
>