We have often heard of fiber optic switches and fiber optic transceivers. Among them, fiber optic switches are high-speed network transmission relay equipment, also called fiber channel switches and SAN switches. Compared with ordinary switches, they use fiber optic cables as transmission equipment. medium. The advantages of optical fiber transmission are fast speed and strong anti-interference ability. There are two main types of fiber optic switches. One is the FC switch used to connect to storage. The other is an Ethernet switch, the port is an optical fiber interface, and the appearance is the same as an ordinary electrical interface, but the interface type is different.
There are three types of fiber switches: entry-level switches, workgroup-level fiber switches, and core-level fiber switches. So let’s start with the first core-level fiber optic switch!
1.core-level fiber optic switches
The so-called core-level switches (also called directors) are generally located in the center of a large SAN, connecting several edge switches to each other to form a SAN network with hundreds of ports. The core switch can also be used as a standalone switch or edge switch, but its enhanced functions and internal structure make it work better in the core storage environment. Other functions of the core switch also include: support for protocols other than optical fiber (like InfiniBand), support for 2Gbps Fibre Channel, and advanced optical services (for example: security, trunk and frame filtering, etc.). Core-level fiber optic switches usually provide many ports, from 64 ports to 128 ports and more. It uses a very wide internal connection to route data frames with maximum bandwidth. The purpose of using these switches is to build a larger coverage network and provide greater bandwidth. They are designed to route frame signals as fast as possible between multiple ports with the shortest delay. In addition, core fiber switches often use hot-swappable circuit boards based on “blade type”: as long as the switch board is inserted in the cabinet, new functions can be added, and online maintenance can also be performed. Need to be expanded. Many core-level switches do not support arbitrated loops or other directly connected loop devices. They only care about core switching capabilities. Because availability is the most important in the entire environment, people are willing to spend more money on redundancy. All components of high-redundancy switches are redundant, which completely eliminates single points of failure and guarantees very long-term Uptime. These expenditures on redundancy are generally spent on high-availability backplanes, power supplies, redundant circuits, and software to maintain availability. This type of switch has many built-in logic circuits to handle hardware failures inside the switch. The core switches in the fiber optic switches provide the highest reliability and port density. In a data center with a large amount of Fibre Channel infrastructure, such products are almost invulnerable, centralized storage switches. Therefore, for most high-availability networks, you should choose a dual-channel network constructed by core fiber switches.
2.workgroup-level fiber optic switches
Fiber optic switches provide the ability to cascade many switches into a large-scale Fabric. By connecting one or more ports of two switches, all ports connected to the switch can see a unique image of the network, and any node on this fabric can communicate with other nodes. Through cascading switches, a large, virtual, distributed switch can be established, and the distance it can span is very large. A fabric built up of multiple switches looks like a fabric composed of separate switches. The ports on all switches can be viewed and accessed like all other ports on the fabric as accessing local switches. The unified name server and management service allow viewing and modifying all Fabric information through a single interface. An important factor in creating a distributed fabric is to obtain the bandwidth of the connection between the switches. The effective rate between any two ports is affected by the effective bandwidth of the connection between the switches, and it may be necessary to use multiple connections between switches to maintain the necessary bandwidth. Workgroup Fibre Channel switches are numerous and more versatile. Workgroup switches are used in many ways, but the most widely used area is small SAN. Such switches can be connected together through interconnection lines between switches to provide more ports. The interconnection lines between switches can be created on any port on the Fibre Channel switch. However, if you plan to use products from multiple vendors, you must ensure that the devices are interoperable.
3.entry-level switches
The application of entry-level switches in fiber optic switches is mainly concentrated in small working groups with 8 to 16 ports. It is suitable for occasions with low prices and little need for expansion and management. They are often used to replace hubs, which can provide higher bandwidth and provide more reliable connections than hubs. People generally don’t buy entry-level switches separately, but often buy them together with other levels of switches to form a complete storage solution. Entry-level fiber optic switches provide a limited level of port cascading capabilities. If users use such low-end devices alone, they may encounter some manageability problems.