[3608] in North American Network Operators' Group
Re: sell shell accounts?
daemon@ATHENA.MIT.EDU (Sean Doran)
Wed Jul 24 03:21:09 1996
From: Sean Doran <smd@chops.icp.net>
To: salo@msc.edu (Tim Salo)
CC: freedman@netaxs.com, nanog@merit.edu
In-reply-to: salo@msc.edu's message of Tue, 23 Jul 1996 17:06:00 -0500 (CDT)
Date: Wed, 24 Jul 1996 03:16:03 +0100
It's still ATM day, 'cause something else just occurred to
me:
| Consider the following configuration
|
| ________ _______________________ ________
| | Router | loop A | | loop C | Router |
| | A |=========| Wide-Area ATM Service |========| C |
| |________| |_______________________| |________|
| |
| | local loop B
| |
| ________
| | Router |
| | B |
| |________|
How is one doing bandwidth allocation in this scheme? Are
we assuming CBR (to be very conservative) (or VBR with V=0
for those that don't do CBR)?
If so, then local loop B is really two circuits, one of
BW X and the other of BW 1-X.
Moreover, continuing with the thought of CBR or the
equivalent, if one has a hundred routers in one's network,
how does one allocate a fixed bandwidth from B to each
router? Or does one overcommit and lean on UBR or ABR or
some other *BR?
These are serious questions I don't have an answer to, and
come a result of having remembered the paragraph below and
of remembering that a couple of our competitors have
very large (admittedly "Frame Relay") PVC meshes.
Sean.
| The desire for a full mesh of VCs between routers becomes more compelling
| if you have more than three routers. The diagram is left as an exercise
| to the reader; I rather dislike having to draw in ASCII.
