Method and system for realizing checksum updating of 1588UDP (User Datagram Protocol) packet in multiple MAC (Media Access Control)

Abstract

The invention provides a method and a system for realizing checksum updating of a 1588UDP (User Datagram Protocol) packet in multiple MAC (Media Access Control). The method comprises the following steps that: a message outlet processing module reads message data, edits a message header and modifies the message data, substitutes a modified 64-bit time stamp or a time modification domain value with 0, and obtains the value of the original 16-bit UDP checksum by calculation; the current 64-bit time stamp is obtained from a PTP (Precision Time Protocol) engine through a message time identification point, and the value of new 16-bit UDP checksum is obtained based on the value of the original 16-bit UDP checksum by incremental computation; and the MAC substitutes the value of the new 16-bit checksum and the 64-bit time stamp for the previous data while transmitting the message to the position on which the data are modified. In the method, the UDP checksum computing mode before the PTP message enters into an MAC end is modified, and the 64-bit original time stamp or the time modification domain value is not needed to be stored in multiple MAC, so that use of a register or a memory is reduced greatly, and design cost of chips is also reduced.

Description

technical field [0001] The invention relates to the technical field of network communication, in particular to a method and system for realizing the verification and updating of 1588UDP encapsulation packets in multiple MACs. Background technique [0002] In order to solve the lack of Ethernet timing synchronization capabilities and the need for distributed network timing synchronization in measurement and control applications, the IEEE 1588 standard defines a precision time protocol for network measurement and control systems, namely the PTP protocol, without additional hardware investment. , using the communication link of the network to achieve clock synchronization, which can achieve microsecond-level synchronization accuracy. When implementing PTP in Ethernet, each PTP message will be encapsulated with MAC (Media Access Control, Media Access Control) encapsulation header, IP (Internet Protocol, Internet Protocol) encapsulation header, UDP (User Datagram Protocol, User ...

AI Technical Summary

Problems solved by technology

[0006] Although this scheme has improved the shortcoming of the MAC in the first scheme to place a memory that can store the entire message, it still needs to use registers or memory to record the original 64-bit time stamp value or 64-bit time correction field before being modified. value

For a single MAC, this implementation is acceptable, but usually an Ethernet switch chip will contain multiple MACs, so this will also increase the cost of the chip

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