Comprehensive Analysis of core router performance indicators

China's core routers have developed rapidly. Here we mainly introduce ten performance indicators of the core routers, including the throughput of the core routers. Speaking of the performance of the core router, I would like to give you a brief introduction to what is a router and what is a router used!

A router is a network device that connects multiple networks or CIDR blocks. It can translate data between different networks or CIDR blocks ", so that they can "read" each other's data to form a larger network. The core router has two typical functions: Data tunnel and control. The data channel functions include forwarding decision, backplane forwarding, and output link scheduling, which are generally completed by specific hardware. The control functions are generally implemented by software, it includes information exchange, system configuration, and system management with adjacent core routers.

Over the years, the development of core vrouters has continued to flourish. In the middle of 1990s, traditional routers became the bottleneck restricting the development of the Internet. Instead, the ATM switch becomes the core of the IP backbone network, and the core router becomes a secondary role. In the end of 1990s, the Internet scale was further expanded, and traffic doubled every six months. The ATM network became a bottleneck, and the vro started again. After the Gbps route switch was launched in 1997, people began to replace the ATM switch with a Gbps route switch, and the backbone network with the core router as the core. I believe that you have a basic understanding of the concept of vro. Let's talk about ten performance indicators of the core vro:

The system switching capability and processing capability of a high-speed router are different from those of a general router. At present, the high-speed Router backplane switching capacity should reach 40 Gbps or above, and even if the system does not provide OC-192/STM-64 interface, this interface must also be supported without upgrading the existing interface card and general-purpose parts in the future. In terms of device processing capability, when the system is running at full capacity, all interfaces should be able to process short packets at line speed, such as 40 bytes and 64 bytes. At the same time, the switching matrix of the high-speed router should be able to process the switching of all interfaces at the wire speed without affecting the traffic type.

One metric: Throughput

Throughput is the packet forwarding capability of the core router. Throughput is related to the number of vro ports, port rate, packet length, packet type, route computing mode distribution or concentration), and test methods. throughput generally refers to the ability of the processor to process packets. The packet forwarding capability of a high-speed router must be at least 20 mpps. Throughput mainly includes two aspects:

1. Machine Throughput

The package forwarding capability of a device is an important indicator of the device's performance. The router selects routes based on the IP header or MPLS label. Therefore, the performance indicator refers to the number of packets forwarded per second. The total machine throughput is usually less than the sum of the throughput of all the ports on the core router.

2. port throughput

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

Indicator 2: route table capability

A Router usually depends on the route table created and maintained to determine packet forwarding. The route table capability refers to the maximum number of route table entries in a route table. Because the core router that executes the BGP protocol on the Internet usually has hundreds of thousands of Route entries, this project is also an important embodiment of the router capability. Generally, the high-speed core router should be able to support at least 0.25 million routes, and each destination address should provide at least 2 routes. The system must support at least 25 BGP peers and at least 50 IGP neighbors.

Indicator 3: backplane capability

Backplane refers to the physical path between the input and output ports. The backplane capability is the internal implementation of the core router. The traditional core router uses the shared backplane, but as a high-performance router, it will inevitably encounter congestion problems. Secondly, it is difficult to design a high-speed shared bus, therefore, the existing high-speed core routers generally adopt the interchangeable Backplane Design. The backplane capability can be reflected in the router throughput. The backplane capability is generally greater than the value calculated based on the throughput and test packet length. However, the backplane capability can only be reflected in the design and cannot be tested.

Metric 4: Packet Loss Rate

Packet loss rate refers to the proportion of data packets that cannot be forwarded due to lack of resources under a stable and sustained load of the core router in the data packets to be forwarded. Packet Loss Rate is usually used to measure the performance of the core router when the router is overloaded. Packet loss rate is related to the packet length and packet sending frequency. in some environments, you can perform test simulation by adding route jitter or a large number of routes.

Metric 5: latency

Latency refers to the time interval between the first bit of a data packet entering the router and the last bit output from the core router. This interval is the processing time of the core router that stores the forwarding method. Latency is related to the packet length and link rate. It is usually tested within the throughput range of the router port. Latency has a great impact on network performance. As a high-speed router, in the worst case, the latency of 1518 bytes or less of the IP packet must be less than 1 ms.

Metric 6: Number of back-to-back frames

The number of back-to-back frames refers to the number of data packets when the maximum number of data packets sent at the minimum frame interval does not cause packet loss. This indicator is used to test the core router caching capability. A core router with full-duplex line rate forwarding capability. The value of this indicator is infinite.

Metric 7: latency Jitter

Latency jitter refers to latency changes. Data Services are not sensitive to latency jitter. Therefore, this indicator is generally not an important indicator for measuring high-speed core routers. This indicator is necessary for testing services other than data on IP addresses, such as voice and video services.