Subject: comments on template specs

From: [email-masked] (John Krawczyk)
Date: Sun, 2 Apr 95 16:01:55 EDT

Comments on the Integrated Service template documents.

o  Ordering of Rspecs

This section should explain what to do when two Rspecs cannot be
compared and if/how to merge them.  For example, if the RSVP LUB
(least upper bound) technique is applicable, the template ordering
section should say so.  I'll also second Fred Baker's earlier comments
on this subject.

o  Optional advertisements (e.g., instantaneous delay)

Given the uncertainty already contained in the specs about how to deal
with nodes that do not advertise optional parameters, here are a few
comments:

The controlled delay document suggests inserting a fixed delay value
when a network element doesn't actually measure it.  In this case, I
think the delay then has to be marked as a "guess" rather than a
measurement.  Also, knowing how many networks elements used guesses
rather than measurements would give the receiver of the advertisement
some idea of the accuracy of the measurement.  There may also be cases
where a network element may want to invalidate the instaneous delay
completely because it knows that whatever it inserts will be wrong.

o  Token bucket parameters (nit)

"b" and "r" are used backwards in many cases.  I'd always thought "b"
was Bucket depth and "r" was bucket Rate.

o  Nonconforming packets - why take a specific action?

It would be helpful if the text said: "Noncomforming packets are
dropped because....".

o  Target delay

The controlled delay and predictive specs mention a "target" delay in
the Invocation section.  What exactly is this delay?  Per-hop?
End-end?

-jj