Core Router 10 performance metrics

The system switching ability and processing ability of high speed routers is an important embodiment of their ability to be different from the general routers. At present, the high speed router's backplane switching capacity should reach more than 40Gbps, and the system, even if the oc-192/stm-64 interface is temporarily not provided, it must be in the future without the existing interface cards and general parts upgrades to support the interface. In terms of device processing capability, when the system is running at full load, all interfaces should be able to handle short packets at wire speed, such as 40-byte, 64-byte, at the same time, the exchange matrix of high-speed routers should be able to handle all the exchange of all interfaces without blocking, regardless of traffic type.

One metric: Throughput

Throughput is the packet forwarding capability of routers. The throughput is related to the number of router ports, port rates, packet lengths, packet types, routing calculation patterns (distribution or centralization), and test methods, which generally refer to the processor's ability to process packets. The packet forwarding capability of a high-speed router is at least 20Mpps above. Throughput includes two main aspects:

1. Overall throughput

The whole machine refers to the package forwarding capability of the equipment, which is an important index of the equipment performance. The router's job is to select the path based on the IP header or MPLS tag, so the performance metric refers to the number of forwarding packets per second. Overall throughput is usually less than the sum of all port throughput of the router.

2. Port throughput

Port throughput refers to the port packet forwarding capability, which is the packet forwarding capability of a router on a port. Typically two identical rate test interfaces are used. Generic test interfaces may relate to interface locations and relationships, such as the throughput of tests between ports on the same card may differ from the throughput values between ports on different cards.

Index Two: Routing table capability

Routers usually rely on the established and maintained routing tables to determine the forwarding of packets. The routing table capability refers to the limit of the number of routing table entries that are accommodated within the routing table. Because routers that perform BGP on the internet usually have hundreds of thousands of routing table entries, the project is also an important manifestation of router capabilities. In general, a high-speed router should be able to support at least 250,000 routes, averaging at least 2 paths for each destination address, and the system must support at least 25 BGP peers and at least 50 IGP neighbors.

Index three: Back plate ability

The back panel refers to the physical path between the input and the output port. Backplane capability is the internal implementation of the router, the traditional router uses shared backplane, but as a high-performance router will inevitably encounter congestion problems, and secondly, it is difficult to design a high-speed shared bus, so the existing high-speed routers generally use interchangeable backplane design. Backplane capabilities can be reflected in router throughput, and backplane capabilities are usually greater than the values calculated based on throughput and test Baochang. But the backplane ability can only be reflected in the design, generally can not test.

Index four: Packet loss rate

Packet loss rate refers to the proportion of packets that cannot be forwarded due to lack of resources in a stable continuous load. Packet loss rates are often used to measure the performance of routers as they overload their work. Packet loss rate is related to packet length and packet sending frequency, in some environments, can be combined with routing jitter or a large number of routes to test simulation.

Index Five: Delay

Delay refers to the time interval at which the first bit of a packet enters the router to the last bit from the router. The time interval is the processing time of the router that stores the forwarding mode. Time delay is related to packet length and link rate, and is usually tested in the range of router port throughput. Delay has a large impact on network performance, as a high-speed router, in the worst case, requires 1518 bytes and the following IP Bao Shiyan are less than 1ms.

Indicator Number SIX: back-to-back frames

Back-to-back frames are the number of packets sent at the minimum frame interval that do not cause packet loss. This metric is used to test router caching capabilities. A router with a linear speed full duplex forwarding capability, the index value is infinitely large.

Index VII: Delay jitter

Delay jitter refers to the time delay variation. The data service is insensitive to delay jitter, so this index is not usually used as an important index to measure high speed routers. For other services, such as voice and video services, which are on IP, it is necessary to test this index.