Analysis of five technical instructions for data center switches

1. High-capacity devices

The network traffic of the data center is characterized by high-density application scheduling and burst buffering. Common switches cannot precisely identify and control services for interconnection purposes, in large business situations, quick response and zero packet loss cannot be achieved, and business continuity cannot be guaranteed. The reliability of the system mainly depends on the reliability of the equipment. As a result, common switches cannot meet the needs of data centers. Data center switches must have high-capacity forwarding features.

The data center switch must support high-density 10-Gigabit boards, that is, 48 10-Gigabit boards. To enable full-line rate forwarding for 48 10-Gigabit boards, the data center switch can only adopt the CLOS distributed switching architecture. In addition, with the popularization of 40G and G, G boards supporting 8-port 40G boards and 4-port G boards have gradually become commercially available. The 40G and G boards of data center switches have already entered the market, this satisfies the needs of high-density data center applications.

2. Large cache technology

The data center switch has changed the outbound port caching method of the traditional switch system. It adopts a distributed cache architecture, and the cache is much larger than that of the common switch. The cache capability can reach more than 1 GB, generally, vswitches can only reach 2 ~ 4 M.

The per-port traffic cache capability reaches 200 milliseconds under 10 gigabit full-line speed conditions. In this way, in the case of traffic bursts, the large cache can still ensure zero packet loss in network forwarding, which is suitable for the characteristics of a large number of data center servers and a large burst of traffic.

3. Virtualization technology

The network equipment of the data center must have the characteristics of high management and high security and reliability. Therefore, the switch of the data center must also support virtualization. Virtualization is to convert physical resources into logically manageable resources, to break the barriers between physical structures.

The virtualization of network devices mainly includes multiple virtual machines, one virtual machine, multiple virtual machines, and other technologies. Through virtualization technology, you can manage multiple network devices in a unified manner, or completely isolate the services on one device, thus reducing the management cost of data centers by 40%, increase IT utilization by about 25%.

4. FCOE technology

Traditional data centers often have a data network and a storage network. The new generation of data center network convergence is becoming increasingly apparent. The emergence of FCOE technology makes network convergence possible, FCOE is a technology that encapsulates data frames of the storage network in Ethernet frames for forwarding. To achieve this convergence technology, it must be on the switch of the data center. Common switches generally do not support the FCOE function.

5. TRILL technology

In terms of building a L2 network, the original standard of the data center is the STP protocol. However, STPs works through port blocking and no data forwarding is performed on all redundant links, this results in a waste of bandwidth resources;

There is only one spanning tree in the whole STP network, and all the datagram files must pass through the root bridge before they can arrive. This affects the forwarding efficiency of the whole network. As a result, STP will no longer be suitable for expansion of super-large data centers. TRILL is based on these STP defects and is a technology for data center applications.

The TRILL protocol combines layer-2 configuration and flexibility with Layer-3 integration and scale effectively. When layer-2 configuration is not required, the whole network can be forwarded without loops. TRILL technology is the basic feature of the second layer of the data center switch, which is not available to common switches.

The above network technologies are not available in common switches. They are the main technologies used in data center switches and the network technologies used to serve the new generation of data centers and even cloud data centers. With these new network technologies, the data center has developed rapidly.