What is the backplane bandwidth and what is the backplane bandwidth of the switch?

The backplane bandwidth of a switch is the maximum amount of data that can be handled between the switch's interface processor or interface card and the data bus. The backplane bandwidth indicates the total data exchange capacity of the switch, which is measured in Gbps, also known as switching bandwidth, and the backplane bandwidth of a general switch ranges from a few Gbps to hundreds of Gbps.

The higher the bandwidth of a switch's backplane, the more data it can handle, but the higher the design cost. The utilization of backplane bandwidth resources is closely related to the internal structure of the switch.

Internal Structure:

First, a shared memory structure, which relies on the central switching engine to provide full-port high-performance connections, and the core engine examines each input packet to decide on routing. This approach requires a lot of memory bandwidth, a lot of overhead, and especially as the number of switch ports increases, the amount of memory becomes high, making the switch core a bottleneck for performance implementation.

Second, the cross-bus structure, which can establish a direct point-to-point connection between ports, which is good for single-point transmission performance, but not suitable for multi-point transmission.

3. Hybrid crossover bus structure, which is a hybrid crossover bus implementation, its design idea is to divide the integrated crossover bus matrix into small crossover matrices, and connect them through a high-performance bus in the middle. The advantage is that the number of crossover buses is reduced, the cost is reduced, and the bus contention is reduced, but the buses that connect the crossover matrix become the new performance bottleneck.

What are the backplane bandwidth, switching capacity, and packet rate?

1. The difference between backplane bandwidth and switching capacity by definition:

1. Backplane bandwidth: The maximum amount of data processed between the switch's data bus and the switch's interface card (or interface processor) is called the backplane bandwidth. The higher the backplane bandwidth, the stronger the data exchange capability of the switch.

2. Exchange capacity: The exchange capacity refers to the amount of exchange ions that can be produced by the ion exchanger in the switch, and the exchange capacity of the switch is affected by many factors, and the biggest factor is the size of the ion exchanger.

2. The difference between backplane bandwidth and switching capacity from the perspective of calculation method:

1. Backplane bandwidth: Backplane bandwidth = 2 Number of ports Corresponding port rate.

2. Exchange capacity: exchange capacity = (concentration of NaOH standard solution and amount of NaOH standard solution) Wet weight of the sample Solid content.

Calculate] How much bandwidth does a switch backplane need?

The larger the backplane bandwidth of a switch, the higher the performance of the switch, the stronger the ability to process data, but the higher the cost. Therefore, it is necessary to choose the appropriate backplane bandwidth to avoid waste. If you want to calculate the appropriate backplane bandwidth of a switch, you need to consider the following two aspects:

Consider 1: The 2-port port capacity is calculated to be less than the backplane bandwidth, so that the switch can be maximized without waste.

Consider 2: To consider the throughput of the switch, when the packet length is 64 bytes, the throughput of 1 Gigabit port of the switch is theoretical), and the throughput of 10 Gigabit ports is.

The bandwidth of the switch backplane that satisfies both of the above aspects is the most appropriate. The bandwidth and throughput of the backplane should be considered, and they should be considered in combination when choosing, not just one side.

The utilization of backplane bandwidth resources is closely related to the internal structure of the switch.

The internal structure of a switch is divided into three types: one is the common memory structure, which requires a large amount of memory bandwidth; The second is the cross-point bus structure, the single-point transmission of the cross-bus mechanism is much better than the multi-point transmission performance, so the cross-bus structure is mostly used in the single-point transmission; There is also a hybrid crossover bus structure, which reduces the number of buses and avoids waste, so it saves a lot of costs.

What are the backplane bandwidth, switching capacity, and packet rate?

The difference between the bandwidth and switching capacity of the switch backplane.

Backplane bandwidth: represents the speed between our interface processor or interface card and the core switching engine, you may all know that we calculate the standard of a backplane bandwidth of a switch to achieve line speed** is "=2*number of ports*port bandwidth", you can also see that the nominal backplane bandwidth of the current switch is greater than our theoretical value, but the actual situation of the switch's line speed ** is not necessarily the case, that is because he is not the most core parameter. The switch backplane is a design value that can be greater than or equal to the switching capacity (this is a criterion for achieving wire-speed switches).

When designing, the manufacturer considers the upgrade of the module in the future, such as the module upgrade from the initial 100 Gigabit to support Gigabit and 10 Gigabit, and the port density increases. Backplane bandwidth generally refers to modular switches. It determines the maximum bandwidth between each template and the switching engine.

is the maximum amount of data that can be handled between a switch interface processor or interface card and a data bus. The backplane bandwidth indicates the total data switching capacity of the switch, which is measured in Gbps, also known as the switching bandwidth.

Switching capacity: It represents the rate of the core switching engine of our switch, which is generally expressed in bps, which is related to the bit width of the buffer and its bus frequency, for example, the cache of a switch is 96 and the bus frequency is 133, then his switching capacity is 96 * 133 = 12....In fact, some engineers of equipment manufacturers already think that the concept of backplane bandwidth is meaningless, and the switching capacity and the ** rate to be mentioned below determine the performance of the switch, and this parameter largely depends on the switch matrix.

Switching capacity (maximum bandwidth, throughput) refers to the maximum ability to exchange data between user interfaces in the system, and the exchange of user data is realized by the fabric. When the switch reaches line speed, the switching capacity is equal to the number of ports corresponding to the port rate 2 (full-duplex mode).

Packet rate: In fact, this packet rate is the packet rate of the third layer, and the exchange capacity above is the packet rate of the second layer. To calculate the Layer 3 packet rate, to put it simply, what is the port rate of Gigabit?

1000,000,000bps*8*(64+8+12)=, 8 represents 8 bits, and 64+12+8 represents a frame with a data field of 64 bytes, the actual number of bytes used for transmission on the network, the header of 8 bytes, and other overheads of 12 bytes. In the same way, the packet rate of the 100 Gigabit interface is Ha. Therefore, in order to achieve our envelope speed in the third layer, we must at least meet this condition, and our envelope rate.

Packet rate: It reflects the performance of the switching engine. Standard Ethernet frame sizes range from 64 bytes to 1518 bytes, and the smallest packet size should be used to measure the packet capability of a switch. Refers to the total amount of data in a unit of time, based on a 64-byte packet, switch**.

The switching capacity refers to the memory of the switch, and the backplane bandwidth refers to the performance of the switch, such as the bandwidth of 8 ports of 10 and 100M, the larger the bandwidth, the better the performance.

The following package rates:

The calculation should be.

1000，000，000bps/8/(64+8+12)=，

What are the backplane bandwidth, switching capacity, and packet rate?

What are the backplane bandwidth, switching capacity, and packet rate?

In general, the calculation is as follows:

1) The wire-speed backplane bandwidth examines the total bandwidth that all ports on the switch can provide. The calculation formula is the number of ports * the corresponding port rate * 2 (full-duplex mode) If the total bandwidth is the nominal backplane bandwidth, then the backplane bandwidth is the line-rate bandwidth.

2) The second layer of the package ** line speed.

Layer 2 Packet Rate.

The number of gigabit ports The number of 100 Gigabit ports * the number of ports of other types * the corresponding calculation method, if this rate can be nominal Layer 2 packet rate, then the switch can only achieve line speed when doing Layer 2 switching.

3) The third layer of the package ** line speed.

Same as the second layer of the package ** line speed.

So, how did you get it?

For 10 Gigabit Ethernet, the packet rate of a wire-speed port is **.

For Gigabit Ethernet.

The packet rate for a wire-speed port is .

For Fast Ethernet, the packet rate for one wire-rate port is .

For a POS port on OC 12, the packet rate for a wire-rate port is .

For a POS port on OC 48, the packet rate for one wire-rate port is .

If the above three conditions can be met, then we will say that this switch is truly linear and non-blocking.

1. What is the difference between backplane bandwidth and switching architecture?

Switching architecture refers to the way data traverses a device. The main ones are:

Bus-type: The packet travels through the bus to all ports, and then the processor tells each port whether to continue or drop the packet.

Shared memory: The packet is placed in shared memory, and then the processor tells the port module that should read the data to the specified location.

Cross-matrix type: The data is sent directly to the module port through the cross-matrix switch. The direction of the route can be determined by the processor, or by the input module itself.

The latter is distributed processing. Generally, only the cross-matrix type can achieve complete distributed processing.

Backplane bandwidth is the sum of bandwidth that can be used for packets to traverse a device. The bus type is the width of the bus, the shared type is the sum of the bus bandwidth of each module reaching the ** processor, and the cross matrix type is the sum of the bus bandwidth of each module connected to the matrix.

The backplane bandwidth is a cross-matrix.

What are the backplane bandwidth, switching capacity, and packet rate?