Electronic Design
IEEE Approves 40/100-Gbit/s Ethernet Standard

IEEE Approves 40/100-Gbit/s Ethernet Standard

After about four years of work, the IEEE 802.3ba Task Force has ratified the 802.3ba Ethernet standard. It covers communications with Ethernet at 40 and 100 Gbits/s across backplanes, copper cabling, multi-mode fiber (MMF), and single-mode fiber (SMF), moving our networking speeds forward by another order of magnitude.

Each Ethernet standard has incremented the data speed by another decade, in this case to an amazing 100 Gbits/s. But unique to 802.3ba is a 40-Gbit/s option that fits many existing applications. It’s a welcome addition to Ethernet, as it continues to scale with the need. Originally a local-area networking (LAN) technology, Ethernet has gone far beyond its roots thanks to a continuous standards effort. The new standard paves the way for the next generation of high-rate server connectivity and core switching.

The 802.3ba standard was designed to maintain the well-known and widely supported Ethernet frame format and the media access controller (MAC), as well as to create new physical layers (PHYs) for 40 and 100 Gbits/s. It also will support full-duplex only and a 10–12 bit error rate (BER) at the PHY/MAC interface. And, it will work with the ITU’s Optical Transport Network (OTN) for long haul networks.

For 40 Gbits/s, the PHYs include 10 km on SMF, 100 m on optical multimode 3 (OM3) MMF, 10 m on copper cable, and 1 m on a backplane. For 100 Gbits/s, the PHY goals include 40 km on SMF, 10 km on SMF, 100 m on OM3 MMF, and 10 m on a copper cable. For the most part, the task force met these objectives except for 10 m over copper cable, specifying a maximum range of 7 m instead. Also, a range of 150 m was achieved at 100 Gbits/s over optical multimode 4 (OM4) MMF. No tricky new modulation schemes are used, and the data format is plain-old NRZ using optical technology.

Other features include the use of 64B/66B encoding for error correction and a mix of PHY options. For example, the 40-Gbit/s and 100-Gbit/s versions for a 100-m reach are based on multiple fibers carrying 850-nm laser data. It also includes four OM3 MMFs for 40 Gbits/s and 10 OM3 MMFs for 100 Gbits/s. For the longer 10-km reach options, the medium is SMF.

Multiple wavelengths of 1270, 1290, 1310, and 1330 nm are used for 40 Gbits/s. With 64B/66B coding, the signaling rate is 10.3125 Gbits/s. For 100 Gbits/s, data is transmitted at 28.78125 Gbits/s over 1295, 1300, 1305, and 1310 nm. All these wavelength-division multiplexed (WDM) formats match up with what the International Telecommunication Union (ITU) specifies for its long-haul optical transport network (OTN) fiber networks.

The 802.3ba standard addresses critical challenges facing technology providers today, such as the growing number of applications with demonstrated bandwidth needs far exceeding existing Ethernet capabilities, by providing a larger, more durable bandwidth pipeline. Furthermore, collaboration between the IEEE P802.3ba 40-Gbit/s and 100-Gbit/s Ethernet Task Force and the ITU’s Telecommunication Standardization Sector (ITU-T) Study Group 15 ensures these new Ethernet rates are transportable over OTNs.

“Ubiquitous adoption of bandwidth-intensive technologies and applications, such as converged network services, video-on-demand, and social networking, is producing rapidly increasing demand for higher-rate throughput,” says John D’Ambrosia, chair of the IEEE 802.3ba Task Force and director of Ethernet-based standards, as well as CTO of Force 10 networks.

“As mass-market access to these technologies continues accelerating, coupled with today’s progressively more powerful server architectures, data centers, network providers, and end users alike are finding themselves confronted by pressing bandwidth bottlenecks,” D’Ambrosia adds. “IEEE 802.3ba will eliminate these bottlenecks by providing a robust, scalable architecture for meeting current bandwidth requirements and laying a solid foundation for future Ethernet speed increases.”

The new standard will act as the catalyst needed for unlocking innovation across the greater Ethernet ecosystem. IEEE 802.3ba is expected to trigger further expansion of the 40-Gbit and 100-Gbit Ethernet family of technologies by driving new development efforts. It also will provide new aggregation speeds that will drive new 10-Gbit/s Ethernet network deployments.

Furthermore, the standard’s ratification dovetails with efforts aimed at delivering greater broadband access, such as the U.S. Federal Communication Commission’s “Connecting America” National Broadband Plan, which calls for 100-Mbit/s access for a minimum of 100 million homes across the U.S.

In addition to providing an increased bandwidth pipeline, IEEE 802.3ba remains compatible with existing IEEE 802.3 installations, preserving significant industry investment in the technology. The standard is also expected to generate concrete benefits, such as lowered operating expense costs and improved energy efficiencies, by simplifying complex link aggregation schema commonly used in today’s network architectures.

Key players waiting to adopt 802.3ba include users and producers of systems and components for servers, network storage, networking systems, high-performance computing, data centers, telecommunications carriers, and multiple system operators (MSOs).

The PDF version of the approved standard is available for purchase at shop.ieee.org. The Ethernet Alliance also has a good white paper on 40/100-Gbit/s Ethernet at www.ethernetalliance.org.

IEEE 803ba Task Force

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