Sunday, 11 December 2011

100 Gigabit Ethernet

40 Gigabit Ethernet, or 40GbE, and 100 Gigabit Ethernet, or 100GbE, are high-speed computer network standards developed by the Institute of Electrical and Electronics Engineers (IEEE). They support sending Ethernet frames at 40 and 100 gigabits per second over multiple 10 Gbit/s or 25 Gbit/s lanes. Previously, the fastest published Ethernet standard was 10 Gigabit Ethernet. They were first studied in November 2007, proposed as IEEE 802.3ba in 2008, and ratified in June 2010. Another variant was added in March 2011.


In June 2007 a trade group called "Road to 100G" was formed after the NXTcomm trade show in Chicago. Official standards work was started by IEEE 802.3 Higher Speed Study Group. The P802.3ba Ethernet Task Force commenced on December 5, 2007 with the following project authorization request:
The purpose of this project is to extend the 802.3 protocol to operating speeds of 40 Gb/s and 100 Gb/s in order to provide a significant increase in bandwidth while maintaining maximum compatibility with the installed base of 802.3 interfaces, previous investment in research and development, and principles of network operation and management. The project is to provide for the interconnection of equipment satisfying the distance requirements of the intended applications.


The 40/100 Gigabit Ethernet standards encompass a number of different Ethernet physical layer (PHY) specifications. A networking device may support different PHY types by means of pluggable modules. Optical modules are not standardized by any official standards body but are in multi-source agreements (MSAs). One agreement that supports 40 and 100 Gigabit Ethernet is the C Form-factor Pluggable (CFP) MSA[6] which was adopted for distances of 100+ meters. QSFP and CXP connector modules support shorter distances.
The standard supported only full-duplex operation. Other electrical objectives include:
Preserve the 802.3 / Ethernet frame format utilizing the 802.3 MAC
Preserve minimum and maximum FrameSize of current 802.3 standard
Support a bit error ratio (BER) better than or equal to 10 − 12 at the MAC/PLS service interface
Provide appropriate support for OTN
Support MAC data rates of 40 and 100 Gbit/s
Provide Physical Layer specifications (PHY) for operation over single-mode optical fiber (SMF), laser optimized multi-mode optical fiber (MMF) OM3 and OM4, copper cable assembly, and backplane.
The following nomenclature was used for the physical layers.


The 100 m laser optimized multi-mode fiber (OM3) objective was met by parallel ribbon cable with 850 nm wavelength 10GBASE-SR like optics (40GBASE-SR4 and 100GBASE-SR10). The 1 m backplane objective with 4 lanes of 10GBASE-KR type PHYs (40GBASE-KR4). The 10 m copper cable objective is met with 4 or 10 differential lanes using SFF-8642 and SFF-8436 connectors. The 10 and 40 km 100G objectives with four wavelengths (around 1310 nm) of 25G optics (100GBASE-LR4 and 100GBASE-ER4) and the 10 km 40G objective with four wavelengths (around 1310 nm) of 10G optics (40GBASE-LR4).
In January 2010 another IEEE project authorization started a task force to define a 40 gigabit per second serial single-mode optical fiber standard (40GBASE-FR). This was approved as standard 802.3bg in March 2011. It used 1550 nm optics, had a reach of 2 km and was capable of receiving 1550 nm and 1310 nm wavelengths of light. The capability to receive 1310 nm light allows it to inter-operate with a longer reach 1310 nm PHY should one ever be developed. 1550 nm was chosen as the wavelength for 802.3bg transmission to make it compatible with existing test equipment and infrastructure.
In December 2010, a 10x10 Multi Source Agreement (10x10 MSA) began to define an optical Physical Medium Dependent (PMD) sublayer and establish compatible sources of low-cost, low-power, pluggable optical transceivers based on 10 optical lanes at 10 gigabits/second each. The 10x10 MSA was intended as an lower cost alternative to 100GBASE-LR4 for applications which do not require a link length longer than 2 km. It was intended for use with standard single mode G.652.C/D type low water peak cable with ten wavelengths ranging from 1523 to 1595 nm. The founding members were Google, Brocade Communications, JDSU and Santur. Other member companies of the 10x10 MSA included MRV, Enablence, Cyoptics, AFOP, OPLINK, Hitachi Cable America, AMS-IX, EXFO, Huawei, Kotura, Facebook and Effdon when the 2 km specification was announced in March 2011. The 10X10 MSA modules were intended to be the same size as the C Form-factor Pluggable specifications.




Backplane


NetLogic Microsystems announced backplane modules in October 2010. This industry trend is important because standards-based 100GE interconnects may allow building optical backplanes at a fraction of price currently required by VCSEL based implementations - such as those in found in multichassis systems from Cisco (CRS) and Juniper Networks (T-series).


Quellan announced a test board, but no module is available.


Multimode fiber


In 2009, Mellanox[18] and Reflex Photonics announced modules based on the CFP agreement.




Single mode fiber


Finisar, Sumitomo Electric Industries, and OpNext all demonstrated singlemode 40 or 100 Gigabit Ethernet modules based on the C Form-factor Pluggable agreement at the European Conference and Exhibition on Optical Communication in 2009.




Compatibility


Optical domain IEEE 802.3ba implementations were not compatible with the numerous 40G and 100G line rate transport systems which feature different optical layer and modulation formats. In particular, existing 40 Gigabit transport solutions that used dense wavelength-division multiplexing to pack four 10 Gigabit signals into one optical medium were not compatible with the IEEE 802.3ba standard, which used either coarse WDM in 1310 nm wavelength region with four 25 Gigabit or four 10 Gigabit channels, or parallel optics with four or ten optical fibers per direction.




Test and Measurement


Ixia developed Physical Coding Sublayer Lanes and announced test equipment in 2009.
JDS Uniphase introduced test and measurement products for 40 and 100 Gigabit Ethernet in 2009. Discovery Semiconductors introduced optoelectronics converters for 100 gigabit testing of the 10 km and 40 km Ethernet standards.
Spirent Communications introduced test and measurement products in 2009 and 2010. Xena Networks demonstrated test equipment at the Technical University of Denmark in January 2011. EXFO demonstrated interoperability in January 2010.
These products verify Ethernet protocol implementation but do not test physical layer compliance to IEEE PMD specifications.




First commercial 100GE systems


Unlike the "race to 10Gbps" that was driven by the imminent needs to address growth pains of Internet in late 1990s, customer interest to 100Gbit/s technologies was mostly driven by economy factors. Among those, the commonly reasons to adopt 100GE were:
Reduction in number of lambdas, ability to stopgap proliferation of lit fiber
Better bandwidth utilization relative to 10Gbit/s link aggregates
Cheaper wholesale, internet peering and datacenter interconnect connectivity
Desire to "skip" the relatively expensive 40Gbit/s technology and move directly from 10Gbit/s to 100Gbit/s
Considering that 100GE technology is natively compatible with OTN hierarchy and there is no separate adaptation for SONET/SDH and Ethernet networks, it was widely believed that 100GE technology adoption will be driven by products in all network layers, from transport systems to edge routers and datacenter switches. Nevertheless, in 2011 components for 100GE networks were not a commodity and most vendors entering this market relied on both internal R&D projects and extensive cooperation with other companies.




Optical Transport Systems


Solving the challenges of optical signal transmission over a nonlinear medium is principally an analog design problem. As such, it has evolved at a slower rate relative to digital circuit lithography advances (which have generally progressed in step with Moore's law.) This explains why 10Gbit/s transport systems have existed since the mid-1990s, while the first forays into 100Gbit/s transmission happened about 15 years later - a 10x speed increase over 15 years is far slower than the 2x speed per 1.5 years typically cited for Moore's law tracking technologies. Nevertheless, as of Aug 2011 at least four firms (Ciena, Alcatel-Lucent, MRV, ADVA Optical and Huawei) have made customer announcements for 100Gbit/s transport systems - although with varying degrees of capabilities. Although most vendors claim that 100Gbit/s lightpaths can utilize existing analog optical infrastructure, in practice deployment of new, high-speed lambdas remains tightly controlled and extensive interoperability tests are required before moving new capacity into service.




Routers and switches with 100GE interfaces


Design of router or switch with support for 100Gbit/s interfaces is not an easy feat for multiple reasons. One of them is the need to process a 100Gbit/s stream of packets at line rate without reordering within IP/MPLS microflows. As of 2011, most components in the 100Gbit/s packet processing path (PHY chips, NPUs, memories) were not readily available off the shelf or require extensive qualification and co-design. Another problem is related to the low-output production of 100Gbit/s optical components, which were also not easily available - especially in pluggable, long-reach or tunable laser flavors. Therefore, in the early days of 100GE, vendors considered this market to be a technology showcase and were not shy to advertise their technological prowess.
In the below historical breakdown of 100GE routing and switching milestones, we keep separate track for the dates of product announcements, trials and revenue shipments (where known).
Alcatel-Lucent
Alcatel-Lucent first announced 100GbE interfaces for their 7450 ESS/7750 SR platform in June 2009, with field trials following in June–September 2010. However, in April 2011 presentation, James Watt (ALU optical division president) still mentioned 100GE technology as "demo" staged for T-Systems and Portugal Telecom. Later, in a June 2011 press-release with Verizon, the company again referenced 100GE as "trial" Thus, despite of being able to bundle the self-developed optical and routing system, Alcatel apparently missed the chance to book early revenue with 100GE deployments.
In a separate press release from June 2011, Alcatel-Lucent announced the new generation of packet processing silicon dubbed FP3, which may hint towards company's strategy and timeline on commercial shipments of 100GE products.
Brocade Communications Systems
In September 2010, Brocade announced their first 100GbE solution to be based on the former Foundry Networks hardware (MLXe). Quite impressively, in June 2011 (less than a year from initial press statement), the new product went live at AMS-IX traffic exchange point in Amsterdam, bringing first-ever 100GE revenue for Brocade. This feat is even more impressive considering that Brocade commonly uses 3rd party network processors and optics. Rumored to be priced around $100K per port, the 2x 100GE linecard for MLXe appears geared for aggressive competition, although it is still unknown whether this product is capable to perform beyond IP peering applications or support long-haul / tunable optics.


Cisco Systems


The joint Cisco-Comcast press release on first-ever 100GE trials went out back in 2008, however it is doubtful this transmission could approach 100Gbit/s speeds when using a 40Gbit/s/per slot CRS-1 platform for packet processing. The need to wait for the next generation of routing hardware can explain the fact that the following milestone for Cisco 100GE program did not happen until March 2010, when field trial in AT&T network added color to launch of a new CRS-3 router. The first 100GE deployments at AT&T and Comcast happened 12 months later, in April 2011. In addition, later in the same year, Cisco have tested the 100GE interface between CRS-3 and the next generation of their ASR9K edge router, although offering no information on hardware availability for the latter.
Huawei
In October 2008, the Chinese vendor presented the "industry's first" 100GE interface for their flagship router, NE5000e. Almost a year later, in September 2009, Huawei also presented an end-to-end 100G solution consisting of OSN6800/8800 optical transport and 100GE ports on NE5000e. This time, it was also mentioned that Huawei's solution had the new self-developed NPU "Solar 2.0 PFE2A" onboard and was using pluggable optics in CFP form-factor. In a mid-2010 solution brief, the new NE5000e linecards were given commercial name (LPUF-100) and were credited with using two Solar-2.0 NPUs per 100GE port in opposite (ingress/egress) configuration. Nevertheless, in October 2010, the company referenced shipments of NE5000e to Russian cell operator "Megafon" as "40Gbps/slot" solution, with "scalability up to" 100Gbit/s.
April 2011 brought a new 100GE announcement from Huawei - now the NE5000e platform was updated to carry 2x100GE interfaces per slot using LPU-200 linecards. In a related solution brief, Huawei reported 120 thousand 20G/40G Solar 1.0 chips as shipped to customers, but no Solar 2.0 numbers were given. Also, following the August 2011 100G trial in Russia, Huawei reported paying 100G DWDM customers, but no 100GE shipments on NE5000e.
Juniper Networks
Juniper first announced the 100GE to come to its T-series routers in June 2009. By this time, the latest incarnation of T-series, known as T1600 has been shipping for almost two years and supported the 100Gbit linecards in 10x10GE configuration. The 1x100GE option followed in Nov 2010, when a joint press release with academic backbone network Internet2 marked the first production 100GE interfaces going live in real network. Later in the same year, Juniper demoed 100GE operation between core (T-series) and edge (MX 3D) routers. Juniper confirmed it's grip of the market again in March 2011, stealing thunder from Cisco by announcing first shipments of 100GE interfaces to a major North American service provider (Verizon[53]). In the meanwhile, the company was apparently busy selling 100GE cards to a host of smaller operators (such as UK's JANET).




Standardization time line


IEEE standardization project history:
Call for interest at IEEE 802.3 plenary meeting in San Diego — July 18, 2006
First HSSG study group meeting — September 2006
Last study group meeting — November 2007
Task Force formally approved as P802.3ba by IEEE LMSC — December 5, 2007
First P802.3ba task force meeting — January 2008
IEEE 802.3 working group ballot — March 2009
IEEE LMSC sponsor ballot — November 2009
First 40 Gbit/s Ethernet Single-mode Fibre PMD study group meeting — January 2010.
P802.3bg task force approved for 40 Gbit/s serial SMF PMD— March 25, 2010
IEEE 802.3ba standard approved — June 17, 2010
IEEE 802.3bg standard approved — March 2011
IEEE 802.3bj 100 Gbit/s Backplane and Copper Cable Task Force PAR approval due — September 2011
P802.3ba Task Force draft release dates:
Draft 1.0 — October 1, 2008
Draft 1.1 — December 9, 2008
Draft 1.2 — February 10, 2009
Draft 2.0 — March 12, 2009 (for working group ballot)
Draft 2.1 — May 29, 2009
Draft 2.2 — August 15, 2009
Draft 2.3 — October 14, 2009
Draft 3.0 — November 18, 2009 (for sponsor group ballot)
Draft 3.1 — February 10, 2010
Draft 3.2 — March 24, 2010
Final — June 17, 2010

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