Analyze the Seven Core Performance of Industrial Routers

Industrial router is a device that uses a public wireless network to provide wireless data transmission to users. Selecting a good industrial router is not that simple, so what is the performance of a good industrial router? Next let us see the seven core performance of industrial routers.

 

Throughput

Throughput is the packet forwarding capability of the core router. Throughput is related to the number of router ports, port rate, packet length, packet type, route calculation mode (distribution or concentration), and test method. It generally refers to the processor's ability to process packets. High-speed routers have a packet forwarding capability of at least 20 Mpps. Throughput mainly includes two aspects: 

Overall throughput

The overall throughput refers to the whole device’s packet forwarding capability, it is an important indicator of the device performance. The job of the router is to select the path according to the IP header or MPLS label, so the performance indicator refers to the number of packets forwarded per second. The overall throughput is usually less than the sum of the throughput of all ports on the core router.

Port throughput
Port throughput refers to the port packet forwarding capability, which is the packet forwarding capability of the core router on a certain port. Two test interfaces with the same rate are usually used. Generally the test interface may be related to the interface location and relationship. For example, the throughput tested between ports on the same card may be different from the throughput value between ports on different cards.

 

Routing table capability

Routers usually rely on established and maintained routing tables to determine packet forwarding. The routing table capability refers to the limit of the number of routing entries in the routing table. Since the core routers that implement the BGP protocol on the Internet usually have hundreds of thousands of routing entries, this project is also an important manifestation of router capabilities. Generally speaking, the high-speed core router should be able to support at least 250,000 routes, providing an average of at least 2 paths per destination address, the system must support at least 25 BGP peers and at least 50 IGP neighbors.

 

Backplane capability

Backplane refers to the physical path between the input and output ports. Backplane capability is the internal implementation of the core router, traditional core routers use a shared backplane, but as a high-performance router, congestion problems are inevitable, secondly, it is difficult to design a high-speed shared bus, so the existing high-speed core routers generally adopt the design of a switchable backplane. Backplane capability can be reflected in router throughput, and backplane capability is typically greater than the value calculated based on throughput and test packet length. However, backplane capability can only be reflected in the design, generally it cannot be tested.
 

Back-to-back frame

The number of back-to-back frames refers to the number of packets when the maximum packet is sent at the minimum frame interval without causing packet loss. This indicator is used to test core router caching capabilities. The indicator value of a core router with wire-speed full-duplex forwarding capability is infinite.

 

Packed loss rate

The packet loss rate refers to the proportion of packets that cannot be forwarded by the core router due to lack of resources in the packets that should be forwarded under a stable continuous load. The packet loss rate is often used to measure the performance of the core router when the router is overloaded. The packet loss rate is related to the packet length and the packet transmission frequency. In some environments, test simulation can be performed after route flap or a large number of routes are added. 

 

Delay

The delay refers to the time interval between the first bit of the packet entering the router and the last bit being output from the core router. The time interval is the processing time of the core router working in the store-and-forward mode. The delay is related to both packet length and link rate, usually it is tested within the router port throughput range. The delay has a great impact on the network performance. As a high-speed router, in the worst case, the IP packet delay of 1518 bytes and below is required to be less than 1 ms.

 

Delay variation

Delay variation refers to delay changes. Data services are not sensitive to delay variation, so this indicator is usually not an important indicator for measuring high-speed core routers. For other services except IP, such as voice and video services, this indicator has the necessity of testing.