nanog mailing list archives

Re: Point to Point Ethernet


From: Saqib Ilyas <msaqib () gmail com>
Date: Thu, 9 Jul 2009 12:03:04 +0500

For the sake of my knowledge (and perhaps that of some others on the list),
I would like to ask if the current work on standards by IETF, ITU and IEEE
not a step to address the issue of seamlessly using Ethernet in the
metro/core?
IETF is working on GMPLS Ethernet Label Switching (GELS), which proposes to
replace the Ethernet control plane (MAC learning, spanning tree etc) by the
GMPLS control plane. This would provide explicitly routed Ethernet LSPs. ITU
seems to be working on Transport MPLS (T-MPLS), and IEEE seems to be at work
on the Provider Backbone Bridge (PBB) standard.
Granted the difficulties and faults with the standardization process, my
question is more concerned with the technical nature.
Thanks and best regards

On Thu, Jul 9, 2009 at 11:51 AM, Tomas L. Byrnes <tomb () byrneit net> wrote:

Overhead shmoverhead.

Seriously, we're fighting over the non-issue. It's not the "wasted"
0.02% of bandwidth (@ 1Gbps) that's the issue. It's the utility of a
"come as you are" "plug and play" network that "Ethernet" (which really
loosely means all IEEE 802 protocols) provides, which the current
carrier networks do not.

If I read the thread correctly, what you really are asking for is the
ability to plug your IEEE compliant gig/10gig switch into a carrier port
and just have it ARP and respond for valid IP addresses on the segment,
as opposed to all the back and forth provisioning, truck rolls, and
interaction with bell-head union workers that the current system
requires.

Now, HOW to accomplish that is an interesting discussion, and the first
valid result will probably be a great business.

That doesn't require breaking Ethernet, using promiscuous mode, or much
except the carriers stopping trying to throw their legacy
circuit-switched requirements onto a packet switched network.

There's plenty of fiber in the ground. Light dark stuff with the new
network, plug it into IEEE 802* compliant layer 2, and IETF compliant
layer 3 infrastructure; and leave the dying Bellcore/ITU network on the
old copper and SONET.


-----Original Message-----
From: sthaug () nethelp no [mailto:sthaug () nethelp no]
Sent: Wednesday, July 08, 2009 11:34 PM
To: tkapela () gmail com
Cc: nanog () nanog org
Subject: Re: Point to Point Ethernet

Best case, you blow 12 bytes on IFG in gig, 20 bytes on
fast-e/slow-e.

As far as I know Gig and 10 Gig (with LAN PHY) are exactly the same
as 10 and 100 Mbps in this respect, i.e. 8 bytes of preamble and 12
bytes of IFG. So you always have an overhead of 20 bytes, no matter
what.

10 Gig with WAN PHY is a whole different ballgame, of course.

Steinar Haug, Nethelp consulting, sthaug () nethelp no





-- 
Muhammad Saqib Ilyas
PhD Student, Computer Science and Engineering
Lahore University of Management Sciences


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