BW0178 NOV 19,1997 11:26 PACIFIC 14:26 EASTERN
( BW)(GIGABIT-ETHERNET-ALLIANCE) Gigabit Ethernet Standard Effort
Continues On-Track For March Ratification Following Montreal IEEE Meeting
Business Editors
CUPERTINO, Calif.--(BUSINESS WIRE)--November 18, 1997--
Fiber Optic Differential Mode Delay Resolution Reaffirms Existing Link Distance Specifications
In keeping with the rapid progress of the Gigabit Ethernet standards activities during the past
year, the Gigabit Ethernet Alliance today announced that the standards process continues on its
aggressive schedule for final ratification in March 1998. The IEEE 802 Plenary meeting, held last
week in Montreal, Quebec, resulted in the conclusion of several important issues. The 802.3z
Gigabit Ethernet Task Force resolved all comments raised during the Working Group Ballot
process, including those related to the recently discovered technical issue of Differential Mode
Delay (DMD) in multi-mode fiber link lengths. Resolution of DMD reaffirmed that current link lengths
for 1000BASE-SX and 1000BASE-LX remain the same. Significant progress was also made by
the 802.3ab Task Force which resolved the last significant technical issue, reviewed the contents
of an initial draft and approved issuance of Task Force base draft 802.3ab/D1.1.
"The outcome of last week's meetings exceeded our highest expectations, including resolution
of the one major technical issue on the 802.3z draft standard," said Bob Grow, Vice Chair,
Technical Liaison of the Gigabit Ethernet Alliance and Industry Relations Vice President for XLNT.
"The approval rate on the Working Group Ballot reached one hundred percent by the end of last
week. This tremendously high rate was possible only through the extreme dedication of task force
members, both prior to and during the meeting."
A notable technical issue raised during an earlier ballot was resolved as a result of intensive
research by a large group of optical experts who comprised a Modal Bandwidth Investigating (MBI)
group. Called Differential Mode Delay (DMD), this condition can occur in situations in which a laser
light source is launched into long multi-mode fibers. Gigabit Ethernet is the first technology to
confront DMD due to its very high baud rate, long multi-mode fiber link lengths, and its rigorous
evaluation of the link technology. DMD exists for any high-speed technology using a coherent
(laser) light source for transmission over multi-mode fiber media. Neither single-mode fiber nor
copper solutions are affected by DMD.
The IEEE 802.3z Task Force and 802.3 Working Group voted overwhelmingly to accept a
modification to the draft standard to address DMD by outlining mandatory "conditioned launch" for
1000BASE-SX and 1000BASE-LX on multi-mode fiber. Initial laboratory and field verification of
conditioned launch for 1000BASE-LX with multi-mode fiber using a hybrid jumper cable has been
successful. Implications of this requirement confirm that there will be no reduction to the link lengths
as specified for -SX and -LX for the short wavelength (260 meters on 62.5 and 550 meters on 50
micron fiber) and long wavelength (440 meters on 62.5 and 550 meters on 50 micron fiber) Gigabit
Ethernet interfaces. Member companies of the Gigabit Ethernet Alliance will assist IEEE standards
participants in further verification testing of the conditioned launch specifications. Additionally,
there is no delay foreseen in the current aggressive 802.3z schedule as a result of Differential
Mode Delay.
Grow explained, "Although the change to the specification adds new requirements for fiber optic
transceivers, optical component vendors stated at the meeting that they believed a majority of -SX
devices already meet the specifications for conditioned launch. For -LX multi-mode, the only
additional requirement is a conditioning jumper cable."
Commented Howard Frazier, Chairman of the 802.3z Gigabit Ethernet Task Force and Network
Architect for Cisco Systems, "I'm extremely impressed with and proud of the work the MBI group
has accomplished in regard to Differential Mode Delay. Considering the fact that in the real world,
most of us are competitors, this achievement is even more impressive. This significant original
research on DMD is a fundamental contribution to the entire networking industry. I'm confident that
what we have documented in our studies will be of great benefit to other high-speed technologies."
The 802.3z Gigabit Ethernet Standard Draft Process Update
Since the last Plenary meeting in July 1997, draft 802.3z/D3.1 was the subject of the 802.3
Working Group Ballot. During interim meetings held in London, England, and Santa Clara,
California, during September, the 802.3z Task Force approved responses generated during the
ballot process and incorporated changes in draft 802.3z/D3.2.
The recirculation ballot to allow review of these changes closed shortly before last week's
Montreal meetings. During the meetings, responses were approved on the comments generated,
the majority of which were editorial in nature, and 802.3z/D3.3 was produced to include the few
technical changes that resulted. The IEEE 802.3 Working Group and 802 Executive Committee
gave approval to move forward with the next step, issuance of the Sponsor Ballot. The successful
completion of the Working Group Ballot, followed by issuance of the Sponsor Ballot, keeps 802.3z
on track for ratification in March.
In keeping with the current aggressive schedule for standardization of Gigabit Ethernet, an
interim meeting of the IEEE 802.3z Task Force will be held in Seattle, Washington, during
February 1998. Upon resolution of all technical and editorial comments, the draft standard will be
issued for Sponsor Ballot, the last step in the standards process. Once any comments generated
at that stage are resolved, the 802.3z draft standard will become a complete Gigabit Ethernet
standard.
802.3ab Task Force Accomplishments
Concurrently, work on the 1000BASE-T physical layer option of Gigabit Ethernet has been
steadily progressing in the 802.3ab Task Force. Issues regarding the last significant technical
issue, start-up procedures, were resolved last week, and a basic protocol was established. A
preliminary specification for 802.3ab was also reviewed, which will result in availability of the Task
Force base draft document, 802.3ab/D1.1, next week.
The IEEE 802.3ab Task Force has its own document production schedules. Current plans call
for two interim meetings, January 12-13, 1998, in Dallas, Texas, and February 16-17, 1998, in
Silicon Valley, California, prior to the next Plenary meeting in March 1998. The plan is to seek
approval for a Working Group ballot in March, with ratification targeted for late 1998.
About the Gigabit Ethernet Alliance
The Gigabit Ethernet Alliance was formalized around four common objectives -- to fully support
the Gigabit Ethernet standards activities being conducted in the IEEE 802.3z Task Force, to
contribute technical resources to facilitate convergence and consensus on technical specifications,
to provide resources to establish and demonstrate product interoperability, and to foster two-way
communications between potential suppliers and consumers of Gigabit Ethernet products. This
multi-vendor effort is committed to providing customers with open, cost-effective and interoperable
Gigabit Ethernet solutions, and it supports the same frame format as the original Ethernet
standard. To date, representatives from approximately 120 networking, computer, component and
test equipment companies are participating in the Gigabit Ethernet standards activities. The
Gigabit Ethernet Alliance headquarters is located in Cupertino, Calif. Phone: 408-241-8904, Fax:
408-241-8918, Email: 73530.2267@compuserve.com, Web Site: www.gigabit-ethernet.org .
Note: A Q&A detailing technical issues cited in this press release is available on the Gigabit
Ethernet Alliance Web Site.
--30--jar/sf*
CONTACT: Marilyn Callaghan
650/342-6087
mcallagh@pacbell.net
KEYWORD: CALIFORNIA
INDUSTRY KEYWORD: COMPUTERS/ELECTRONICS
gigabit-ethernet.org
I tried here but the Q&A wasn't there,Yet.
Anyone found it? Please let us know where?
Thanks
John LoBianco |
