[28166] in North American Network Operators' Group
Re: UBR at MAE-East ATM, anyone?
daemon@ATHENA.MIT.EDU (Kevin Oberman)
Tue Apr 18 14:12:53 2000
Message-Id: <200004181810.LAA18227@ptavv.es.net>
To: Alex Rubenstein <alex@nac.net>
Cc: nanog@merit.edu
In-reply-to: Your message of "Tue, 18 Apr 2000 13:09:35 EDT."
<Pine.WNT.4.05.10004181256100.948-100000@kerplewie.nac.net>
Date: Tue, 18 Apr 2000 11:10:42 -0700
From: "Kevin Oberman" <oberman@es.net>
Errors-To: owner-nanog-outgoing@merit.edu
Ah! This is a bit different from what was previously said, but not
that different. Mostly replace SCR with MCR.
You can specify an absolute PCR for an ABR PVC (total traffic, both
tagged and untagged (clp0+1)). This is typically done to prevent a
faster input circuit from overwhelming a slower output circuit, e.g a
PVC from an OC-12 source to a DS-3 destination, but I can't imagine why
simply someone would specify PCR as twice MCR as opposed to capping it
at the speed of the destination circuit or some other hardware
enforced limit.
Steve, any chance you could shed some light on this?
> <snip>
>
> > 3) is it still VBR, or UBR/ABR now?
>
> It's actually implemented as ABR, with the peak cell
> rate enforced and set to twice the reserved rate.
>
> </snip>
Alex, where did this come from? I've never seen this and would love to
have a reference. There is no documentation on http://www.mae.net/atm/
as far as I can see and I didn't see this in the Peermaker manual
(although I could have missed it).
R. Kevin Oberman, Network Engineer
Energy Sciences Network (ESnet)
Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab)
E-mail: oberman@es.net Phone: +1 510 486-8634
