Analyze the bandwidth standard calculation method of the vswitch Backboard

The backboard bandwidth is the maximum amount of data that can be transferred between the vswitch interface processor or interface card and the data bus. The higher the bandwidth of the backboard of A vswitch, the stronger the ability to process data, but the design cost will also rise.

However, how can we check whether the bandwidth of A vswitch is sufficient? Obviously, the estimation method is useless. I think we should consider the following two aspects:

1. The sum of the total port capacity X ports should be 2 times smaller than the backboard bandwidth, enabling full-duplex non-blocking switching, proving that the switch has the conditions to maximize the data exchange performance.

2. Full configuration throughput (Mpps) = number of fully configured GE ports x 1. 488Mpps the theoretical throughput of One gigabit port when the packet length is 64 bytes is 1.488 Mpps. For example, A vswitch that can provide up to 64 Gigabit ports must have a full configuration throughput of 64 × 1.488 Mpps = 95.2 Mpps to ensure that all ports are working at the same speed, provides non-blocking packet switching. If a vswitch can provide a maximum of 176 Gigabit ports and the declared throughput is less than 261.8 Mpps (176x1.488 Mpps = 261.8 ), the user has reason to think that the switch adopts a blocking structure design.

Generally, the switches that both meet the requirements are qualified switches.

A vswitch with a relatively large backplane and a relatively small throughput retains the ability to upgrade and expand it to software. The design of a dedicated chip circuit is problematic. A vswitch with a relatively small backplane and a relatively high throughput, the overall performance is relatively high. However, the Board bandwidth can be believed by the manufacturer, but the throughput cannot be believed by the manufacturer. because the latter is a design value, the test is very difficult, and the significance is not great.

The back-end speed of a vswitch is generally Mbps, which refers to the second layer. Mpps is used for switching between three or more layers.