I would only add that the number of
connectors for MMF is also more than the 4 used in the loss calculation.
I have been reminded of this numerous time both by people from inside IBM,
as well as outside.
So, let us do it right this time.
Peter
Petar Pepeljugoski
IBM Research
P.O.Box 218 (mail)
1101 Kitchawan Road, Rte. 134 (shipping)
Yorktown Heights, NY 10598
Please respond to
Mike Dudek <Mike.Dudek@JDSU.COM>
To
STDS-802-3-HSSG@LISTSERV.IEEE.ORG
cc
Subject
Re: [HSSG] HSSG Reach Ad Hoc "Rides
Again"
Please note that the 2dB traditionally
used for the SMF link budgets is 2dB for connector and
splice losses. I
also note that the loss for MTP connectors (not Elite) is 0.5dB typical
1.0dB max per connector (compared to 0.15dB typical 0.3dB max for LC) ,
so using our normal worst case criterion if they are MTP there could only
be 2 connectors. The attenuation figures I have listed above are
from a quick search so I’d encourage any installers or others who have
better information to join this thread.
Mike
From: John DAmbrosia [mailto:jdambrosia@FORCE10LABS.COM]
Sent: Monday, November 19, 2007 11:14 AM
To: STDS-802-3-HSSG@LISTSERV.IEEE.ORG
Subject: Re: [HSSG] HSSG Reach Ad Hoc "Rides Again"
Chris,
Thanks for bringing this up.
Further information on connector loss would be useful for this call.
John
From: Chris Cole [mailto:chris.cole@FINISAR.COM]
Sent: Monday, November 19, 2007 12:30 PM
To: STDS-802-3-HSSG@LISTSERV.IEEE.ORG
Subject: Re: [HSSG] HSSG Reach Ad Hoc "Rides Again"
During discussion of the 100GE
SMF reach objective at the Atlanta meeting, an interesting new perspective
was given on how optics are used in the data center. Specifically, it was
suggested (for example by Ted Seely of Sprint) that the number of connectors
used in typical connections is much higher then the 4 or 5 connectors assumed
in SMF link budgets. For these applications, the availability of a 10km
link budget (in the 10GBASE-LR standard) has allowed supporting this higher
number of connectors over data center reaches shorter then 10km.
As part of the HSSG Reach Ad
Hoc, it may be beneficial to quantify the distribution of number of connectors
in links as part of the effort to quantify the distribution of link reaches.
We may still choose to use 2dB as an allocation for connector loss (corresponding
to 4 or 5 connectors) in SMF link budgets, but would use this additional
information to determine the best reach objectives. Further, we may include
informative information as part of the standard to give guidance on how
long reach optics can be used for shorter reach applications requiring
a large number of connectors.
Chris
From: Andy Moorwood [mailto:amoorwood@EXTREMENETWORKS.COM]
Sent: Monday, November 19, 2007 8:27 AM
To: STDS-802-3-HSSG@LISTSERV.IEEE.ORG
Subject: [HSSG] HSSG Reach Ad Hoc "Rides Again"
Colleagues,
At the Atlanta meeting several presentations
were made in the area of requirements for, and relative cost of, reaches
lower than 10km over single mode fiber. In the spirit of promoting
consensus building in the group John has asked me to organize a conference
call so we can have further discussion prior to the interim meeting in
January.
I will forward contact information to the
reflector shortly but would ask those members interested in these issues
to mark in their calendars for a conference call at 9am to 11 am
(U.S. Pacific time zone) on Thursday December 6th.
Presentations from Atlanta may be found on
the study group web site, links to some of the more relevant presentations
are included here for convenience.
For the December conf call it would really
help the group if we could receive further contributions on :
a)
the need for a sub
10km SMF reach
b)
relative costing information
for the different reaches
As of now the agenda for the call is as follows
1. discussion
of the reach and relative costing presentations made at Atlanta
2. discussion
of any new material posted to the reflector
3. discussion
of how to resolve