From: Masataka Ohta <mohta@necom830.cc.titech.ac.jp>
Message-Id: <9402240512.AA08437@necom830.cc.titech.ac.jp>
Subject: Re: URN to URC scenario
To: dupuy@smarts.com (Alexander Dupuy)
Date: Thu, 24 Feb 94 14:11:55 JST
In-Reply-To: <9402240247.AA28196@brainy.smarts.com>; from "Alexander Dupuy" at Feb 23, 94 9:47 pm
> So there appears to be consensus that DNS would only be used to find the
> URN->URL servers (URN->URC servers, in Mitra's scenario). This is true for
> all the DNS configurations being discussed, whether they use TXT, A, or CNAME
> records, a new URN.INT domain or existing DNS domains.
The indirection is important to make use of wild card of DNS.
The other approach is to use TXT records with "transfer" mechanism now
being developed in DNS load balancing sub working group. White paper
is expected to be published soonly. Bind will support it. The mechanism
is essentially the same as the indirection but users does not have to
know complex binary format as it makes use of DNS textual format of zones.
> It's
> also possible to have multiple TXT records with the same name, to spread the
> load of URN->URC lookups across multiple servers - you can't do that with
> CNAMEs (it's possible if you use A records, but then you are tying the
> multiple servers to specific IP addresses, which is inconvenient if those
> addresses ever need to change).
A reasonable approach for the indirection is to use PTR RR.
> In any case, everyone else
> but me seems to feel the DNS records for locating URN->URC servers should be
> in some URN.INT domain;
How can you use local domains for pointing?
BTW, why not use the toplevel domain URN or URN.ARPA? I think INT is
for international organizations.
> I would hope that the DNS administrators for that
> domain would be able to configure a TXT record correctly.
IANA will be the administrator, I think.
> Successfully configuring a new delegated subdomain is a lot more complicated
> than adding a TXT record,
Among all the scheme for distributed database with some redundancy and
caching, I think DNS is the easiest to configure.
> and if the TXT (or CNAME) records for URN->URC
> servers are all in one URN.INT zone because nobody can get their DNS
> administrators to set up a new DNS zone, the domain servers for URN.INT will
> be pretty overworked in five or ten years.
Yes, if some distributed database is difficult to configure delegation,
the central server will be overloaded. So, why not use the scheme
proven to work.
Masataka Ohta