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Why 10 km RE: Going the distance


10 km is what we Ethernet vendors are doing today with 1000BASE-LX interfaces.
Some of these applications are very large campuses, others are the equivalent to
private "MANs", others are GbE access to some facility that is not owned by the
customers (a MAN).  I have proposed 10 km as a goal for the HSSG because GbE
customers will want to run 10 GbE over the same links also some PHY vendors seem
to think the goal is feasible at reasonable cost.

Perhaps 15 km would be a better number since it is based on established MAN


"Perkins, Drew" <drew.perkins@xxxxxxxxxxxx> on 07/01/99 02:42:03 PM

Sent by:  "Perkins, Drew" <drew.perkins@xxxxxxxxxxxx>

To:   "'Howard Frazier'" <hfrazier@xxxxxxxxx>, "'stds-802-3-hssg'"
cc:    (Bruce Tolley/HQ/3Com)
Subject:  RE: Going the distance

I have an interesting question about 3 km vs. 10 km. If the objective is 10
km in order to work in MANs, then this objective seems like a telco
objective. Telcos are used to buying either 2 km (SR) or 15 km (IR) or 40/80
km (LR for 1310/1550 nm) equipment. I do not know this for a fact, but I
would presume that telcos have built out their physical plant taking 15 km
into account. If so, then 10 is not as useful. On the other hand, DSL specs
don't exactly conform with voice specs for copper lines, and in the end
people and carriers learn to cope :-).

Ciena Corporation                 Email: ddp@xxxxxxxxxxxx
Core Switching Division                 Tel: 408-865-6202
10201 Bubb Road                         Fax: 408-865-6291
Cupertino, CA 95014              Cell/Pager: 408-829-8298

-----Original Message-----
From: owner-stds-802-3-hssg@xxxxxxxxxxxxxxxxxx
[mailto:owner-stds-802-3-hssg@xxxxxxxxxxxxxxxxxx]On Behalf Of Howard
Sent: Thursday, July 01, 1999 1:16 PM
To: stds-802-3-hssg@xxxxxxxx
Subject: Re: Going the distance

I accept Bob Grow's ammendment to the motion that Rich made and I seconded.

I would like to encourage every one to think of this motion as incremental
progress.  If we adopt the motion, we will have a solid starting point,
and we can add other distance objectives, or revise the numbers stated
in this objective, at any time before we ballot the standard.

As far as the 2-3 km vs 10 km debate, I agree that 10 km would be
preferable.  I must point out that if we wind up with 10 km, we would
have met an objective that required only 3 km.  If, in the course of
writing the standard, we find that 10 km can readily be achieved at
some acceptable cost premium over 3 km, then we would most likely write
the specification in support of 10 km.

Howard Frazier
Cisco Systems, Inc.