[jdev] Re: Two questions regarding JEP-0124 HTTP Binding

[Peter Saint-Andre]

Norman Rasmussen wrote:
> A comment in JEP-0156 confuses me:
> 
> 3.1: A domain SHOULD NOT present information in DNS TXT records that
> is available via the DNS SRV records defined in RFC 3920.
> 
> At first I read that as '_xmppconnect IN TXT "_xmpp-client-tcp'
> shouldn't be allowed, because the SRV records advertise the same data,
> or am I mis-reading something here?

Yes. SRV records are used to define the stuff in RFC 3920. TXT records 
would be used to define other connection methods, such as (1) support 
for JEP-0124 and the URL at which to access the HTTP-connection service 
or (2) support for connections via WAP and the URL to use.

> Surely it would actually be a _good_ idea to include the port numbers
> in the TXT record, bcause you reduce the number of DNS lookups?  (i.e.
> if you get a TXT record, don't bother with SRV)

The standard XMPP port numbers are to be included in SRV records. It's 
not good to define the same information in two places (what if the 
fumble-fingered DNS admin defines _xmpp-client-tcp as 5222 in SRV but as 
6222 in TXT?) and we already have a place to define ports for 
_xmpp-client-tcp and _xmpp-server-tcp.

So the rule is:

1. Use SRV records for the _xmpp-client-tcp and _xmpp-server-tcp 
connection methods

2. Use TXT for all other connection methods

BTW, this is necessary (especially for HTTP access methods) because you 
can't include a URL in SRV.

Peter
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