DNS-based RR mechanisms

[Abdullah Rayhan <rayhan@ee.ryerson.ca>]

I find the discussing in the request-routing known mechanisms
not very accurate when describing the possible approaches in
which RR is implemented to start with. Also the title is
supposed to reflect the content but it goes as "known" while
the content presents possible cases. The discussion is
interesting in itself but does not reference how things are really
implemented,

For example, sec 2.3 talks about how multiple specialized RR-DNS
servers are to be used to distribute complex decisions from
single server. The motivation behind this, I believe, is
load balancing but this is poorly said and primitive in application.
RR-DNS server will perform the same functionality as a DNS server.
The difference is being authorative over what domain which is
the CN or the content provider if you like. Another difference
might be is how load balancing is achieved through more elaborate
mechanisms than being presented. Load balancing between surrogates
or multiple RR-DNS servers? That needs to be said clearly as well.

In the same section it goes on to mix NS and CNAME records
without any refs. As a matter of fact, this is not allowed
in DNS. You need an A record to go with NS record; DNS experts
correct me if I am wrong. The example mentioned does make
sense but the discussion should be around load balancing
and not RR mechanisms.

The discussion goes on in sec 2.3.1. The NS redirection
is part of the DNS hierarchy and not RR. What this means
is that the CN zone file can be a subdomain of the original
provider domain. For example, news.soandso.com, news is
resolved by CN RR-DNS server via DNS redirection rather
than soandso.com. The same argument applies to section 2.3.2
when requests are redirect via DNS to the CN domain but
CNAME are not returned, NS and A records are.

The discussion of Anycast is theoretical and I doubt if
there is any DNS implementation that makes use of it.
It is not even documented and we dont know how it
works. It is better if is dropped from the draft.

I hope that the authors would take these comments
into consideration to clarify the presentation of Section
2. Comments for other sections will follow at a latter time
so not to have long emails.

my 2 cents.

regards
Abdallah Rayhan