Gigabit Ethernet Standard Effort Continues On-Track For March
Ratification Following Montreal IEEE Meeting
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 440 meters on 50 micron fiber) and long wavelength (550
meters on either 62.5 or 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.
CONTACT: Marilyn Callaghan
650/342-6087
mcallagh@pacbell.net |
