Re: [HSSG] fault signalling
As Hugh pointed out, there is the clause 57 link OAM that might be a
starting point for addressing your requirements. Note though, that it
resides above the MAC.
For most of the PHY proposals in front of the committee there are
several physical lanes/links (e.g., 4x25G or 4x10G) associated with a
single 100G or 40G MAC.
So the performance event notifications and flags (e.g., Errored Symbol,
Link Fault) would apply over the aggregate of the physical lanes/links,
unless there were extensions added to c57 to allow indications on a per
constituent lane/link granularity, as well as support for the raw counts
from the PHY lanes.
Which leads to another issue. For APL above the PCS, as in
frazier_01_1106.pdf, the raw counts could be provided per PCS. For APL
below the 64/66 PCS, as in gustlin_01_0907.pdf, the raw counts would
need to somehow be provided per PMA physical lane (not virtual).
So a question for clarification on your requirement is whether
indications per constituent link granularity or overall aggregate are
For reference, there is an EFM Link OAM (c57) tutorial at:
David W. Martin
+1 613 763 3874 (esn 393)
From: Mikael Abrahamsson [mailto:swmike@SWM.PP.SE]
Sent: Tuesday, September 18, 2007 3:42 PM
Subject: Re: [HSSG] fault signalling
On Tue, 18 Sep 2007, Trowbridge, Stephen J (Steve) wrote:
> I was just thinking about the reasonableness of your installation
> scenario ...
> If I order analog voice service from Qwest, Qwest sends somebody to my
> house to verify the connectivity to their central office and turn up
My Telco won't do that. They will just take for granted that the copper
> If I order cable modem service from Comcast (6 Mbit/s), Comcast sends
> someone to my house to verify connectivity to their network, do
> extensive checks on my cabling at home (how I have my splitters
> configured, making sure that everything except the cable modem jack is
> filtered so that I don't leak anything back into their Cable TV
> distribution network, and that the service works).
My telco won't do that. They will send a description on how to connect
modem in the package they will send you, containing splitter, modem and
cable. It's very unusual that they will send anyone to my home, and if
they do (because I can't get it working) and it's my fault, they'll
me at least $100 for sending an engineer.
> Is it realistic to think that for a bleeding edge service at over
> times the bandwidth of any service I have to my house, that this will
> occur by letting the customer install and connect their own equipment
> over an unverified run of dark fiber and I expect to turn up that
> service from one end of the fiber at the service provider POP without
> sending anyone to the customer premises?
I don't understand your analogy. Do you really expect 100GE to be a
technology used to the customer premesis?
I know how we turn up everything from 1GE to OC768. We expect to connect
equipment at each end of the dark fiber and check attenuation and RX
optical levels so they're within parameters, and then we ping a million
packets and check for CRC errors, if it works error free, we start using
it for live traffic. Engineer in the field will in the best of cases
a optical level meter, most often he does not, he will definately not
an OTDR. We then contiously monitor error rates on the interface.
I don't understand your way of doing business, it sounds hugely
opex-wise, and even then you think that having management in the devices
is a too costly proposal?
I just don't get it. First management is (too) costly to include in
then as an alterantive the proposal is to spend man-hours using very
expensive testing equipment to test the connection before it's used to
turn-up the service? I'd rather spend that money on OAM, my guess is
it'll be cheaper in the long run.
Mikael Abrahamsson email: firstname.lastname@example.org