Liaison Report IEEE 802.3 CSMA/CD Plenary Meeting March 11-14, Hyatt Regency, La Jolla, CA Minutes of the 802.3 HSSG Technical Agenda Summary - key developments ============================ 1. The HSSG received PAR approval from 802 2. Several technical papers were presented 3. A joint authorship/ownership proposal from the chairs of 802.3 and 802.12 was rejected The primary goal of the HSSG (High Speed Study Group) going into the 802.3 plenary session was PAR (Project Authorization Request) approval. Eight pages of questions from other 802 groups regarding the objectives and specific language of the PAR were addressed by the working group. The PAR was granted, giving the HSSG the authority to create and circulate drafts. The final set of objectives, as unanimously approved by IEEE 802.3, are: Set of Objectives for IEEE P802.3z (Gigabit Ethernet) 1. Speed of 1000 Mb/s at the MAC/PLS service interface 2. Use 802.3/Ethernet frame format 3. Meet 802 FR, with the possible exception of Hamming Distance 4. Simple forwarding between 1000, 100, 10 5. Preserve min and max FrameSize of current 802.3 Std 6. Full and Half Duplex operation 7. Support star-wired topologies 8. Use CSMA/CD access method w/ support for at least 1 repeater/collision domain 9. Support Fiber media and if possible copper media 10. Use ANSI Fiber Channel FC-1 and FC-0 as basis for work 11. Provide a family of Physical Layer specifications which support a link distance of: a. At least 500 m on multimode fiber b. At least 25 m on copper (100 m preferred) c. At least 2 km on single mode fiber 12. Decide between collision domain diameter of >= 50m or >= 200m 13. Support media selected from ISO/IEC 11801 14. Accommodate proposed P802.3x flow control Adopted by HSSG, 1/12/96, Y:38, N:0, A:9 Affirmed by HSSG 3/15/96, Y:61, N:0, A:3 In addition to the business of PAR approval, several technical presentations were made. Del Hanson of Hewlett Packard presented a paper from the perspective of an optics component provider, addressing operation at 1.0625 vs. 1.2500 Gbps. Stan Swirhun (Vixel) presented an overview of the optical power budget at 1.25 Gbps. Pat Gilliland (Methode) showed test results of 1.0625 Gbps and 1.25 Gbps data rates at distances of 500m and 1m, contrasting the extrapolated eye- opening at a BER of 10-12. Alister Black (Gadzoox) explained the components of jitter and how Fibre Channel is specifying jitter standards to give a high reliability of interoperable (vs. simply functional) components. He discussed how this work is extensible to the 1.25 Gbps rate. Sailesh Rao (SDE) showed preliminary simulation results of 1Gbps over 4- pair UTP-5, concluding that a split passband approach was feasible. He suggested future work to be done in the areas of latency, signaling details, and echo-cancellation for full duplex operation. Michael Jay Lieb (Technitrol) presented a tutorial-style paper on gigabit transmission over copper media. Michael made a case for cost-effective high speed signal transmission over copper (vs. fiber) at short and medium (< 200m) distances. Results were achieved with signal equalization based on Tecnitrol products. A scheduled report by Motoyasu Yano on the performance of the Sony 1.25 Gbps 10-bit Serdes was not presented. Andy Bechtolsheim (Granite) presented a proposal for using 8B/10B coding and delimiters. He concluded that the 32-bit delimiters (Jordered setsK) used by Fibre Channel were overkill for Ethernet, which needs a total of only 5 delimiters. He also found that 8-bit delimiters would not be compatible with existing silicon and would require a 125Mhz clock. According to Andy, the delimiter size of choice for Ethernet is 16-bits since it is compatible with existing silicon and allows a 62.5 Mhz clock. Andy further recommends the K28.5 character as the first character of the pair. Proposed characters are SOF, pos & neg disparity EOFs, pos & neg disparity JAMs, FILL (special delimiter to allow carrier extension), a special alignment character to pad odd-byte frames to 16-bit boundaries, and two flavors of IDLEs to distinguish between half and full duplex capability. Rich Taborek (Amdahl) presented an overview of the use of 8B/10B by Fibre Channel, as well as other FC building blocks. His discussion included an introduction to ordered sets, OFC, bit and word synchronization, link initialization, reset and recovery procedures, and FC use of delimiters. Rich made a case for preservation of the 32-bit ordered set used by FC into Gigabit Ethernet, and proposed methods for extending FC ordered sets to support FILL, JAM, PAD, and SOF/EOF. Goals would include allowing common components to support both MAC and FC-2 protocols, and take advantage of cost/multi-function economies. Jonathan Thatcher (IBM) presented link start up issues and made an economic case against arbitrarily changing the data rate from 1.062 Gbps to 1.25 Gbps "because we can". Howard Frazier (Sun) presented the results of lab testing done with off-the shelf 100Mbps Ethernet components and Fiber optic links to simulate the proposed scaling of the frame size and collision domain. The experimental results showed that increasing the slot time and minimum carrier duration will not significantly degrade throughput for full size packets. Mohan Kalkunte () presented similar conclusions based on simulation, rather than experimental, results. The correlation between experiments and simulation was very good, and the conclusion was that CSMA/CD at 1000 Mbps on 200 meter topologies is technically feasible. Ahmad Nouri presented the results of a Market Survey commisioned by Compaq and prepared by Currid and Company. The survey revealed the following about ATM, Ethernet, and other transports: Reported Cable Infrastructure: Cat 5 Cat 3 Coax Multi-mode fiber Single mode fiber (62%) (25%) (5%) (4%) (1%) Fast Ethernet variants are defined for all of the above media. Gigabit Ethernet is proposed for all but Cat 3 (cable too slow). Overall Technology Deployment (which companies deploy which technologies) Ethernet Fast Ethernet FDDI Token Ring ATM 100VGanyLAN Sw Ethernet (34%) (18%) (24%) (21%) (1%) (1%) (.7%) Current Backbone Technologies: FDDI Ethernet Fast Enet Sw Enet Token Ring ATM Router/Bridge (37%) (29%) (8%) (8%) (8%) (5%) (5%) Technology Selection Criteria (selected as #1 criteria) Implementation Cost (24%) Raw Bandwidth (20%) Protocol Support (19%) Network Operating System support (18%) Preservation of Management Expertise (13%) Vendor Support/Standards (3%) Availability/Reliability (1%) Wayne Rickard (Emulex) presented an offer of cooperation and liaison between ANSI X3T11 and 802.3 HSSG. He presented an overview of the approved ANSI projects related to Gigabit transmission, the division of work between various X3T11 working groups, and a schedule of upcoming meetings. A straw poll was taken to see if there was interest in assigning a liaison for 802.3 to attend ANSI meetings. There was unanimous approval for supporting this, however because of the time/travel commitment involved, it was felt company approval would be needed for a volunteer. A surprise motion by the chairs of 802.3 and 802.12 took the working group off guard. A Jstatement of cooperationK was drafted that essentially said Jfor full duplex gigabit Ethernet, the needs of the user community would be best served by a single standard, jointly authored and credited to both the CSMA/CD (802.3) and Demand Priority (802.12) camps.K The most heated debate of the plenary ensued, with all the history of the schism that tore the original 100Mbps group into two subgroups flavoring many of the comments. It was finally agreed that the two groups would not formally merge their efforts at any level. A less drastic statement was drafted, stating that "802.3 would look forward to hearing proposals to cooperate with 802.12 in areas of mutual interest." These areas are likely to include definition f PHY, optical specifications, and auto negotiation. Attending the plenary from the X3T11 community were Alistair Black, Kurt Chan, Wayne Rickard, Rich Taborek, Jonathan Thatcher, Shelto VanDoorn, and Gary Warden. Thanks to Howie Johnson and Rich Taborek for additional information not in my original meeting notes! -- end --- The final 5 criteria, as affirmed by HSSG, approved by 802.3, and by 802 Exec. ====================================================== 1. Broad Market Potential o Broad set(s) of applications o Multiple vendors, multiple users o Balance cost, LAN vs. attached stations ------------------------------------------------------------------------- The fast growth of CPU speed is forcing the development of new LANs with higher bandwidth. The following applications and environments will benefit from this capability: o Backbone, Server and Gateway connectivity o Higher Bandwidth for multimedia, distributed processing, imaging, medical, CAD/CAM, and pre-press applications o Aggregation of 100Mb/s switches o Upgrade for large installed base of 10/100 Ethernet Multiple vendors and users have demonstrated interest by attending the Gigabit Ethernet tutorial (over 200 participants), attending the preliminary study group meeting (over 120), and enrolling in the higher speed E-Mail reflector (over 210). 81 participants representing at least 54 companies indicate that they plan to participate in the standardization of 1,000 Mb/s 802.3. This level of commitment indicates that a standard will be supported by a large group of vendors. This in turn will ensure that there will be a wide variety of equipment to support a multitude of applications. Higher-speed 802.3 solutions, which include scaled up versions of existing 802.3 topologies, have balanced cost. Prior experience with scaling 802.3 across the range of 1 to 100 Mb/s indicates that the cost balance between adapters, cabling, and hubs, remains roughly constant, provided that the operating speed can be achieved within the limits of current technology. ================================================= 2. Compatibility with IEEE Standard 802.3 o Conformance with CSMA/CD MAC, PLS o Conformance with 802.2 o Conformance with 802 FR ------------------------------------------------------------------------- The proposed standard will conform to the CSMA/CD MAC, with currently authorized extensions, appropriately adapted for 1000 Mb/s operation. In a fashion similar to the 100BASE-T standard, the current physical layers will be replaced with new Physical Layers (PHY) as appropriate for 1,000 Mb/s operation. The proposed standard will conform to the 802.2 LLC interface. The proposed standard will conform with the 802 Functional Requirements Document (with the possible exception of Hamming distance). The CSMA/CD access method will not support a 2 km network diameter at this speed while maintaining the current values in the MAC parameter table. This portion of the application space will be addressed at 1,000 Mb/s with the full duplex operating mode of 802.3. ===================================================== 3. Distinct Identity o Substantially different from other 802.3 specs/solutions o Unique solution for problem (not two alternatives/problem) o Easy for document reader to select relevant spec ------------------------------------------------------------------------- The proposed standard is an upgrade for 802.3 users, based on the 802.3 CSMA/CD MAC, running at 1,000 Mb/s. Maximum compatibility with the installed base of over 60 million CSMA/CD nodes is maintained by adapting the existing CSMA/CD MAC protocol for use at 1,000 Mb/s. Established benefits of CSMA/CD and the 802.3 MAC include: o Optimistic transmit access method o High efficiency in full-duplex operating mode o Well-characterized and understood operating behavior o Broad base of expertise in suppliers and customers o Straightforward bridging between networks at different data rates The Management Information Base (MIB) for 1,000 Mb/s 802.3 will maintain consistency with the 802.3 MIB for 10/100 Mb/s operation. Therefore, network managers, installers, and administrators will see a consistent management model across all operating speeds. The proposed standard will encompass one Physical Layer solution for each specific type of network media (e.g. single mode fiber, multi-mode fiber, coaxial cable, balanced pair cable). The proposed standard will be a supplement to the existing 802.3 standard, formatted as a collection of new clauses, making it easy for the reader to select the relevant specification. ================================================== 4. Technical Feasibility o Demonstrated feasibility; reports - - working models o Proven technology, reasonable testing o Confidence in reliability ------------------------------------------------------------------------- Technical presentations, given to 802.3, have demonstrated the feasibility of using the CSMA/CD MAC in useful network topologies at a rate of 1,000 Mb/s. Technical presentations given to 802.3 from multiple current vendors of Full Speed Fibre Channel components have demonstrated the feasibility of physical layer signaling at a rate of 1.06 GBaud on both fiber optic and copper media. Many of these vendors have expressed support for an increase in the signaling rate to 1.25 GBaud, which would support a MAC data rate of 1,000 Mb/s. The principle of scaling the CSMA/CD MAC to higher speeds has been well established by previous work within 802.3. The 1,000 Mb/s work will build on this experience. The principle of building bridging equipment which performs rate adaptation between 802.3 networks operating at different speeds has been amply demonstrated by the broad set of product offerings that bridge between10 and 100 Mb/s. Vendors of full speed Fibre Channel components and systems are building reliable products which operate at 1.06 GBaud, and which meet worldwide regulatory and operational requirements. ====================================================== 5. Economic Feasibility o Cost factors known, reliable data o Reasonable cost for performance expected o Total Installation costs considered ------------------------------------------------------------------------- Cost factors are derived from the current Full Speed Fibre Channel component supplier base. A reasonable cost increase (3X of 100BASE-FX) with a ten-fold increase in available bandwidth in the full duplex operating mode will result in an improvement in the cost/performance ratio by a factor of 3.33 for multi-mode fiber applications. The provision for a half duplex operating mode using the 802.3 CSMA/CD MAC will permit the construction of very inexpensive repeating hubs. Customers will in many cases be able to re-use their existing fiber that has been installed in accordance with ISO/IEC 11801. Installation costs for new fiber runs based on established standards are well known and reasonable. Costs for coaxial based short run copper links are well established for full speed Fibre Channel. While the cost model for the horizontal copper cabling is well established, the cost model for 1000 Mb/s physical layers which will operate on horizontal copper cabling has not yet been firmly established. Presentations have been given to the HSSG which suggest a cost multiple of 2X relative to 100BASE-T2. ====================================================== Status Approved by the 802.3 HSSG, 1/12/96. Y:26, N:0, A:3 Affirmed by the HSSG, 3/13/96 Y:52, N: 0, A:0 ======================================================