Throughput refers to the amount of data (measured in bits, bytes, etc. ) successfully transmitted to the network, equipment, ports or other facilities in unit time, that is to say, throughput refers to the maximum data rate that equipment can receive and forward without losing frames.

Throughput is mainly determined by the hardware of internal and external network ports of network equipment and the efficiency of program algorithms, especially program algorithms. For devices that need a lot of operations, the inefficiency of the algorithm will greatly reduce the traffic.

2. Bandwidth

Throughput and bandwidth are confusing words. When discussing the bandwidth of a communication link, it generally refers to the number of bits that can be transmitted per second on the link, which depends on the link clock rate and channel coding. It is also called line speed in computer network, which means that the bandwidth of 100 Mbps Ethernet is 100Mbps.

However, it is necessary to distinguish the available bandwidth (bandwidth) on the link from the number of bits that can be transmitted per second (throughput) in the actual link. Generally, the word "throughput" is more suitable to represent the performance of the network. Because in reality, it is affected by various inefficient factors (such as dual communication network card equipment, link state, etc.). ), a pair of nodes connected by a link with a bandwidth of 100Mbps may only achieve a throughput of 50Mbps. This means that an application on one host can only send data to another host at a speed of 50Mbps.

3. Packet forwarding rate

For network equipment, in addition to throughput, there is also a main indicator, which is packet forwarding rate, which is often called packet forwarding rate. Packet forwarding rate generally refers to the full-duplex throughput of 64-byte packets, including both throughput indicators and packet forwarding rate indicators.

The measurement standard of packet forwarding rate of line speed port is based on the shortest Ethernet packet (Layer 2 or Layer 3 packet) in IEEE802.3, and its formula is as follows: Packet forwarding rate (pps) = throughput /(84 bytes× 8 bits).

So:

For 100 Mbps Ethernet, the packet forwarding rate of a line speed port =100,000,000 bps/672 bit = 0.148 mpps.

For Gigabit Ethernet, the packet forwarding rate of the line speed port is = 1, 000,000,000 bps/672 bit =1.488 mpps.

For 10 Gigabit SFP ports (Ethernet ports have no 10 Gigabit ports), the packet forwarding rate of a line-speed port is =10,000,000,000 bps/672 bit =14.88 mpps.