Method for rapidly generating an ICMP error message

Abstract

The present invention discloses a method for rapidly generating an ICMP error message. During an exchanging network of high speed table look-up, it is required to split an IP data table with an uncertain length into several or hundreds of cell data with a determined length for high speed table look-up. The method directly collects and processes effective information in the cell data to generate an ICMP error message regarding the cell data failing the table look-up, which solves the problem of recombining the cell when the ICMP error message is generated after the cell data fails the table look-up. Using the method of the present invention, the ICMP error message can be directly generated regarding the cell data failing the table look-up, achieving the goal of rapid response. For one IP data table, the first two of the cell data, which are obtained by splitting, need to be processed at most, and the ICMP error message can be generated, thereby reducing processing complexity of generating the ICMP message, and saving soft / hard resources achieved by the system.

Description

technical field [0001] The invention relates to a method for quickly generating ICMP error messages, belonging to the technical field of error message generation in satellite communications. Background technique [0002] IP provides a connectionless, unreliable, and non-confirmed datagram delivery mechanism, which brings two problems while effectively utilizing network resources. One is the lack of error control mechanism; the other is that there is no design-assisted host management and query mechanism. . In order to solve these two problems, ICMP (Internet Control Message Protocol, ie, Internet Control Message Protocol) was proposed to report error information or provide information that needs to be queried to the source router in the network. ICMP is the Internet Control Message Protocol, which transmits error information and query message information between the sender and the receiver. The ICMP protocol can be divided into two categories according to its functions: one...

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Problems solved by technology

[0003] In the switching network for high-speed table lookup, it is necessary to split the variable-length IP datagram into several or even hundreds of fixed-length cell data for high-speed table lookup. Generate the ICMP destination unreachable error message, according to the existing processing method: one, the cell data is reorganized into the original IP datagram before splitting, and the information required for generating the ICMP message is extracted by the IP datagram, according to the ICMP purpose The destination unreachable message format generates an ICMP message. This method additionally increases the cell reassembly process, which not only cannot respond to the error message in time, but also requires more software and hardware resources; The text only needs part of the information of the original IP datagram, and the information required to generate the ICMP message in the IP datagram can be stored separately before the IP datagram is split. If the table lookup fails, the information can be directly extracted. This method can respond quickly. However, in a switching network, the probability of IP datagram table lookup failure is generally small. If each IP datagram stores part of the information, the required cache space is too large, which reduces the resource utilization of the system; The metadata is regarded as a special IP datagram, and an ICMP message is generated for each error cell. Because the cell data does not necessarily contain all the information of the original IP datagram, the generated ICMP message cannot accurately feedback error information, and if Each cell generates an ICMP message, which greatly increases the number of error messages, reduces the transmission efficiency of IP datagrams in normal communication on the link, and leads to a drop in link throughput.

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