Subject: Redirection to correct mailing list

From: [email-masked]
Date: Wed, 29 Jul 1998 12:44:06 -0700

----- Begin Included Message -----

>From [email-masked] Wed Jul 29 04:21:31 1998
From: [email-masked]
Date: Wed, 29 Jul 1998 19:56:07 +0900
To: [email-masked]
Subject: Peak rate parameter [p] in Tspec handling rule.
X-Mailer: mnews [version 1.18PL3] 1994-08/01(Mon)
Sender: [email-masked]
Precedence: bulk
Content-Length: 2314
X-Lines: 65

Folks,

I would like to reinforce my understanding about [p] parameter in Tspec.
According to relating RFC documents(*1), legal range of [p] must be
"0 < p < 40 (Tera byte)" or "Positive Infinity".

        (*1) RFC2210, RFC2211, RFC2212

For both controlled-load and guaranteed services, operational rules
for Tspec can be summarized as follows.

        ---------+------------+--------------+----------
         Compare | Merge      | Least common | Sum
         (*2)    |            | Tspec        |
        ---------+------------+--------------+----------
         p1 > p2 | MAX(p1,p2) | MAX(p1,p2)   | Sum(p)
        ---------+------------+--------------+----------

        (*2) Condition to judge p1 is "larger" than p2.

Resulting from the fact that [p] can be positive infinity, which needs
special handling to give a meaning of indeterminate, my confusion arises.
Under normal arithmetic operation, there is no problem.

For comparison;

	---------+-----------+--------------------------
	   p1    |    p2     | MAX(p1,p2)
	---------+-----------+--------------------------
        infinite | infinite  | infinite (Take p1)
        infinite |   finite  | infinite (Take p1)
          finite |   finite  |   finite (Take p1 or p2)
	---------+-----------+--------------------------

For summation;

        infinite + infinite = infinite
        infinite +   finite = infinite
          finite +   finite =   finite

But, how about for the Tspec case?
I think that above rules, only for [p], should be replaced as follows.

For comparison;

	---------+-----------+--------------------------
	   p1    |    p2     | MAX(p1,p2)
	---------+-----------+--------------------------
        infinite | infinite  | infinite (Take p1)
        infinite |   finite  |   finite (Take p2)        <--- !!!
          finite |   finite  |   finite (Take p1 or p2)
	---------+-----------+--------------------------

For summation;

        infinite + infinite = infinite
        infinite +   finite =   finite  <--- !!!
          finite +   finite =   finite

The principle here is to honor finite [p], since it has concrete
knowledge about network characteristics.

I do appreciate any comments or corrections.
----------------------------------------------------------------------------
Masahiko ENDO / Surigiken Co.,Ltd.

----- End Included Message -----