Parallel route searching method and system for eliminating longest prefix match search

Abstract

The parallel search method and system for eliminating the longest prefix matching search belong to the technical field of Internet high-speed 'address search, and are characterized in that it is based on a binary tree search structure and divides all routing prefixes into prefixes according to the principle that the node heights of current nodes are equal. ; Then, carry out the search of the next hop out port forwarding information in parallel with a highly versatile search framework for several non-overlapping prefix sets divided by the above steps; the search system contains in turn: distributor, bank Unit set, selector and mapping table, described distributor and selector are made of field programmable gate array (being called for short FPGA), and described mapping table is made of synchronous static memory (being called for short SRAM), and described bank unit set is made of FPGA Composed in series with SRAM. It also proposes a method for prefix balancing the set of prefixes. Experiments prove that: it improves the search speed.

Description

technical field [0001] The parallel routing search method and system for eliminating the longest prefix matching search belong to the technical field of high-speed IP address search in the Internet. Background technique [0002] Routers are responsible for routing and forwarding packets in the network. When forwarding a packet, the router needs to perform a route lookup in the routing table based on the destination IP address of each packet header, and find the correct next-hop exit of the packet. In high-performance routers, the interface rate is getting higher and higher. OC48 (2.5Gbps), OC192 (10Gbps), and even higher rate interfaces have been applied in high-performance routers. Under the OC192 interface rate, the router needs to forward 30 million packets per second (the length of the packet is calculated as 40 bytes), that is, it needs to perform 30 million route lookups per second. Fast route lookup technology becomes the key to improve router forwarding performanc...

AI Technical Summary

Problems solved by technology

[0003] The class-based address structure was adopted in the early days of the Internet. With the development of the Internet, the class-based address structure has two problems: 1. A large number of addresses are wasted

2. The scale of Internet global routing table grows exponentially

TCAM also has disadvantages: high cost, high power consumption, and complex update

The leaf pushing technology can reduce the complexity of routing lookup, but there are two problems: 1. It leads to a large amount of repeated routing information

The routing information of the intermediate node is spread to multiple leaf nodes. Initially, one route of the intermediate node is expanded into multiple routes, which causes a waste of storage space.

2. Complicated updates

Since it is assumed that routers are not connected to shared links, this division method is obviously not universal

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