Analysis of various technical parameters of access layer Switches

Some minor differences can determine the performance of a vswitch, which is the same for access layer switches. Therefore, when selecting a vswitch, we need to carefully understand its parameter indicators. In network equipment, switches may be the most familiar equipment for network administrators, especially access layer switches. However, when purchasing switches, many brands seem to have identical technical parameters, network administrators may be confused. So what are the nuances of different vswitches? The following describes the most common access layer switch.

The first is whether PoE power supply is supported. This technical indicator is often ignored by most people. Because the access layer switch directly connects to the terminal, the biggest benefit of the PoE Power Supply switch is that it can easily access other devices. In today's enterprise LAN, terminal devices are no longer limited to computers, wireless APs, IP phones, IP cameras, etc., and will all be connected to switches, these devices are often installed in areas that are inconvenient to access power, such as walls and ceilings. If the switch does not support the PoE power supply function, the network manager can only change the access layer switch.

Therefore, when purchasing an access layer switch, simply consider purchasing an access layer switch with PoE power supply, saving time and effort. In terms of PoE power supply, another indicator worth attention is the power provided by each port. In general, the PoE function adopts the 802. 3af standard, which sets 3.84 ~ 12.95W: five levels of Electric Power requests, up to 13 W. However, because the power required by different AP, IP phone, or camera is different, the larger the PoE power provided by each port, the better.

The second is the number of VLANs and the number of ports aggregated. Different VLANs are divided for each working group, which is the most familiar operation for network administrators. It is also a 24-port switch, but the number of supported VLANs varies a lot. Some support 64, and some support up to 256. Obviously, the larger the number, the better. You can divide more VLANs.

The third thing to note is the number of MAC address tables. The number of MAC addresses refers to the maximum number of MAC addresses that can be stored in the MAC address table of the access layer switch. The more MAC addresses are stored, the higher the speed and efficiency of data forwarding. However, each port of a vswitch of different grades can support different MAC numbers. Each port of the vswitch requires sufficient cache to remember these MAC addresses. Therefore, the Buffer capacity determines the number of MAC addresses that the corresponding access layer switch can remember. Generally, a vswitch only needs to remember 1024 MAC addresses, while a general access layer switch can do this. However, if you consider the expansion of Enterprise Networks in the future, you should select a larger number for the MAC address table, so that you can have more options during the expansion without frequent switch replacement, this greatly reduces the total cost of ownership of vswitches.

The fourth value is the backboard bandwidth. The larger the value, the better. Because the larger the backboard bandwidth, the higher the forwarding capability of the switch. However, the bandwidth is generally related to the number of ports and the speed, the formula is as follows: number of ports * corresponding port rate * 2 (full duplex mode). If the total bandwidth is less than or equal to the nominal backboard bandwidth, the bandwidth is linear. Obviously, when selecting a 24-port switch, you only need to consider the number of its Mbit/s and Gbit/s ports to calculate the bandwidth value of the backboard. Therefore, when selecting a vswitch, it makes little sense if only the bandwidth of the backboard is large. As long as the port speed meets your own requirements and the working mode can support full duplex.

The fifth thing to note is the QoS function. In the current LAN, it is not only data, but also IP voice and video transmission. In addition, some employees often use the company's network to download some movies, play SNS games and other non-work content, which will occupy the bandwidth of the LAN, thus affecting others' work. Although network administrators can purchase professional devices such as internet behavior management and traffic management to manage the behaviors of these users, for small enterprises with limited budgets, the procurement of these devices may not necessarily be approved by the enterprise management. At this time, selecting a access layer switch with QoS function can solve the urgent needs of network administrators to some extent.

The sixth is the Web management interface. The Web interface configuration and management are very convenient and easy to operate, which greatly reduces the configuration workload for the network management. However, the current vswitches are basically Web interfaces. Security is also a factor that needs to be considered. A switch can reject or limit 1 ~ according to ports, MAC addresses, IP addresses, and other indicators ~ Layer-4 network access also provides the ability to deal with common security threats such as multicast, broadcast, and flood control. After explaining the considerations for purchasing 24-port switches, we recommend a cost-effective product: CISCO SRW224G4P 24-port gigabit network management switch.