Ethernet (40g/100g) and basic cabling for next-generation data centers

One, data center and next generation Ethernet

Since the introduction of the Ieee802.3ae standard in 2002, the speed of the Ethernet network has been greatly developed, such as Amsterdam and Tokyo Internet Core Exchange node traffic has exceeded 600Gbps, although 10G The transmission rate of BPS has greatly exerted the potential of common multimode fiber and twisted pair. But with the development of the network application, especially now the network video, the mobile phone intelligence and so on many kinds of business rapid development today, 10GBase already manifests the limitation. In mid-November 2009, Intel began selling the 10GBASE-T network card. It can be foreseen that the power consumption of 10gbase-t will be further reduced with the maturity of IEEE802.3AZ standard and the improvement of chip technology. In the future, PC servers and even ordinary computers will use 10Gbps Ethernet networks.

So after the 2006 10G BASE-T Standards, the IEEE based on the trend of network development, in June, the establishment of the HSSG (higher Speed Study Group) research group. And in December 2007 approved par (Project Authorization Request) to develop the next generation Network 40g/100g Ethernet standards. The next-generation standard IEEE 802.3BA will be introduced in June 2010, according to the plan. 40G and 100G at present, the future of the application is mainly concentrated in the data, when the server a wide range of 10gbase-t, the speed of core exchange must be followed by a significant increase. At the same time, the technology of FCOE,ISCSI in the data center makes the convergence of San/lan network become a trend, which also puts forward higher requirements for the rate of Ethernet network. And now Ethernet also faces such as InfiniBand the highest can support 120G transmission technology competitive pressure, so the introduction of new standards is imminent.

Currently in the core switch market, a considerable number of switch manufacturers have announced that their switch Backplane has supported the 100G standard, juniper and other manufacturers have begun to promote the 100G Ethernet interface board, in the terminal market, 40G Ethernet network card has been launched, such as Mellanox Launched in September 2009 ConnectX-2 EN 40G PCIe network card, support IEEE Draft p802.3ba/d2.0 40GBASE-CR4,-SR and other protocols. Unlike the Mellanox monopoly InfiniBand chip, the IEEE 802.3BA chip competition will be more intense, the future price advantage of the product will be very obvious.

40G and 100G Ethernet in the end is what, to put it simply is to increase the rate of Ethernet to 40gbps/100g bps. This will involve changes in Mac parameters, physical layers, and management sections. This article mainly introduces the physical basis of 802.3BA, because the current standards are still in the draft (D3.0) phase, not finalized, so this article may be introduced in the future and the standards will be slightly different. But the underlying physical link has not changed much, so we need to have a general understanding of the next generation network in order to think about future upgrades, when we're creating a new data center.

Second, 40g/100g and wiring system

There are generally several ways to increase the rate of transmission: 1 more efficient coding, 2 greater transmission bandwidth, and 3 multiplexing.

In the million era, the application of OM3 and CAT6A greatly increased the bandwidth of transmission, coupled with the improvement of chip technology and DSP processing capabilities to make the coding more efficient, and ultimately enable the million Gigabit Ethernet can be promoted. However, after the million trillion, the first medium to increase the transmission bandwidth is not obvious, OM4 to the OM3 and cat7a cat6a have only increased more than twice times the bandwidth, if you want to achieve 100G transmission rate, you must make breakthroughs in other areas. But to improve the coding efficiency of the way to improve bandwidth is faced with two major bottlenecks: 1 The increase in coding efficiency is the use of electromagnetic wave transmission, optical transmission coding efficiency is difficult to improve greatly. 2 The increase of coding efficiency leads directly to the increase of processing cost and requires more expensive equipment. There are other factors such as the urgency of time, to prevent the monopoly of technology and other aspects of the requirements, leading to the current research direction in parallel and multiplexing systems. The biggest advantage of adopting the scheme is that it can draw lessons from the past standards, reduce the development and development of new components, accelerate the introduction of new standards and reduce the cost of the system. Just as the multi-core CPUs are doing their way.

At present, the 40g/100g Ethernet standard mainly has the following several: