How can small and medium enterprises select suitable Ethernet switches?

Fiber Channel-based Ethernet switches are currently very popular. Do you need to select an appropriate Ethernet switch for your SAN or LAN? There are many similarities between SAN and LAN. For example, they all provide data storage and sharing. At the same time, there are also many differences between the two. To make a fair comparison result, let's talk about the differences between the two.

LAN (LAN) generally refers to Ethernet, which is based on IP addresses and can easily achieve low cost and high efficiency with a standard interface. On the other hand, the LAN Based on Fiber Channel puts the data integration level guarantee and efficient performance first, and pays little attention to cost issues.

To evaluate the advantages and disadvantages of these two technologies, you must first have a clear understanding of your own needs. First, you must specify what you must have, what you need, and what you want. Which storage network do you plan to use? If you plan to use a NAS-based storage network, the file sharing protocol uses NFS (Network File protocol), CIFS (General Internet File System), or AppleTalk (Apple

Protocol group), you can select a Traditional Ethernet-based switch. If you plan to use an iSCSI-based storage network, you can also select an Ethernet switch or a switch that supports both the fiber channel and iSCSI technology. The hardware environment Using Fiber Channel supports open systems and the ibm s/390 (zSeries) Environment Based on FICON fiber switches.

You can use the high-speed inbound route selection or storage and forwarding architecture to achieve switching. Many vswitches are designed based on the CLOS architecture. CLOS is named to commemorate Dr. Charles Clos, a researcher at Bell Labs. The switch exchanges data from the source address to the destination address based on the data frame and data packet address. Theoretically, a vswitch can achieve a non-blocking full-speed exchange at no cost. In fact, if the network is overloaded, data congestion may occur, in this case, you can adjust it through Qos and traffic control management software. Traditional vswitches and networks are designed without overload, which can achieve higher performance and therefore be more expensive.

The LAN switch supports a speed from 10 m to 10G. The transmission medium uses copper wires or optical fiber cables, and the port ranges from several to several hundred. This type of switch generally supports TCP/IP and UDP, IPX, and AppleTalk protocols. Other features of this type of switch include: support for VoIP (IP-based voice service), QoS (service quality evaluation), bandwidth management and automatic report generation, support for multicast and ultra-long frame processing. Some switches can also use expansion cards to implement routing and other network functions, including SONET/SDH (Optical Synchronous Network/Synchronous Digital System) and SDH (Synchronous Digital System) and WiFi (Wireless Network ). Vendors of LAN switches include 3Com, Alcatel, Avaya, Cisco Systems, Inc ., dell, D-Link, Enterasys, Extreme, Foundry, Fujitsu, HP, Linksys, Marconi, NEC, SMC and Tasman Networks.

The storage LAN products are mainly based on fiber channels. Small products include embedded switches behind the storage controller, which only have several ports. Large products have hundreds of ports for large systems. Supported protocols include the open system SCSI Optical Fiber Channel Protocol (SCSI_FCP a.k. a. FCP) and the FICON protocol supporting the IBM mainframe environment. Currently, the storage LAN switches have two major speeds: 1G and 2G. Most vendors believe that the next major speed should be 4G and 10G. At the same time, this type of Ethernet switch provides many new security protection features, IP-based storage features, and advanced storage service features, including virtualization technology. Some products also support Ethernet/IP blade systems, and also support iSCSI, iFCP (Internet Optical Fiber Channel Protocol), or FCIP (IP Fiber Channel) that supports remote storage) technology. Producers of storage LAN include Broadcom, Brocade, Cisco, CNT, Emulex, Maranti, Maxxan, McData and Qlogic.

Generally, if you plan to use a storage network that supports fiber channels, you can select an Ethernet switch based on fiber channels. If you plan to use an IP-based (iSCSI, iFCP, FCIP, NAS) storage system network, you can choose a traditional LAN switch, such as an Ethernet switch. A storage network router is a very useful technology that enables protocol conversion between a fiber-optic network and a LAN and the division of a storage LAN. After considering the selected network type, note the following before selecting an Ethernet switch:

Should the performance of each port of your system be consistent or focused?

In order to achieve better performance, how should we develop future expansion plans?

What level of practicality and redundancy does your network need?

What are your network scale and structure requirements when connecting to other Ethernet switches?

How many switch connections (ISL) and serial connection/upload interfaces do you need?