Evaluate the performance of a Gigabit Switch

Currently, there are many types of GE switches and manufacturers that support the Gigabit Ethernet technology on the market. How can we select suitable devices among these devices, it is a problem that requires careful consideration, time-consuming understanding, and difficult to weigh the choice.

Therefore, when evaluating and selecting devices, we should pay attention to the following aspects: product type; 1-gigabit port density and type supported by the product; product performance; after-sales service, manageable features, and security and reliability of products. When purchasing, you are reminded to pay attention to the following main parameters:

● Port

In terms of application: there are currently three types of port-based combinations: Pure MB port products, MB and GB port hybrid products. Pure GB products use different network environments for each product, if it is applied to the core backbone network, it is best to choose a full Gigabit product. If it is on the backbone network, select a gigabit + Gigabit hybrid product. If it is edge access, if you have more budget, you can choose a hybrid product. If you have less budget, you can directly use the original pure MB product.

Performance Indicator: vswitch port performance indicator mainly refers to the number of data packets that can be processed by each port per second. The larger the value, the stronger the switch performance. If you want to purchase a working group switch, we recommend that you select a 10/100 Mbps switch with 24 or 48 ports. If you consider the overall performance improvement, it is also a good choice to mix Mbit/s with Mbit/s or Gbit/s, for a central switch, we recommend that you select a pure Mbps switch with a fixed port.

At present, the market is able to provide m + M mixed port Gigabit Switch products and pure Gigabit Switch products.

● Throughput

The maximum throughput value is referred to as the line rate, which means that the switch has sufficient capacity to process data packet forwarding of various sizes at full speed. All Gigabit Switch products should reach the line rate. Many Gigabit Switch products, such as the SPEED Networks 2400 series, can achieve the full line SPEED. However, this indicator has little practical significance for stackable 10 M/M edge switches.

● Forwarding Rate

The forwarding rate is a very important parameter of a vswitch. It fundamentally determines the forwarding rate of the vswitch. The forwarding rate is usually expressed as "Mpps" Million Packet Per Second, millions of packets Per Second), that is, the forwarding rate Per Second. The forwarding technology can be divided into storage forwarding and pass-through forwarding. Currently, most gigabit switches support storage forwarding. Although direct-through forwarding has a low latency, it will bring spam packets to the exchange network. Therefore, it is generally applicable to network environments with good network link quality and few error packets. The 2400 series Gigabit Switches of SPEED Networks adopt the storage and forwarding technology.

● Board bandwidth

The backboard bandwidth refers to the maximum amount of data that a vswitch interface processor, interface card, and data bus can process. Because communication between all ports must be completed through the backplane, the bandwidth provided by the backplane becomes the bottleneck for concurrent communication between ports. The larger the bandwidth, the higher the available bandwidth that can be provided to each communication port, the faster the data exchange speed. The smaller the bandwidth, the smaller the available bandwidth that can be provided to each communication port, the slower the data exchange speed. Therefore, the higher the bandwidth, the faster the switch transmission rate.

● Cache

Each vswitch maintains a MAC address table, which records the relationship between the MAC address and the port, so that access requests are directly forwarded to the corresponding port based on the MAC address. The more MAC addresses are stored, the higher the speed and efficiency of data forwarding, and the stronger the anti-MAC address overflow supply capability.

● Number of MAC addresses

Cache is used to temporarily store data waiting for forwarding. If the cache capacity is small, the data will be discarded when the concurrent traffic volume is large, leading to network communication failure. Only when the cache capacity is large can we provide better overall performance when the multicast and broadcast traffic is large, while ensuring the maximum possible throughput. Currently, almost all cheap switches use the shared memory structure. All ports share the switch memory, balance network loads, and prevent packet loss.

● Management Functions

Currently, switch vendors generally provide management software or remote management switches that meet the requirements of third-party management software. Generally, the switch supports the snmp mib I/MIB II statistical management function, while complicated gigabit switches support the RMON active monitoring function through the built-in RMON group mini-RMON. Some switches also allow external RMON probes to monitor the network conditions of the available ports.

● Virtual LAN

By dividing a LAN into virtual network vlan cidr blocks, network management and network security can be enhanced to control unnecessary data broadcasts. In a virtual network, a broadcast domain can be a virtual network segment consisting of any selected MAC addresses. In this way, the division of working groups in the network can break through the geographic location restrictions in the shared network, but is completely divided according to the management function. Good products currently provide more detailed functions of virtual network division.