Clock synchronization method and system

Abstract

The embodiment of the invention discloses a clock synchronization method and system. The clock synchronization method comprises the following steps that: a controller acquires clock information transmitted by a switch in an SDN (Software Defined Network), determines a master clock according to the clock information, generates a synchronization file, and instructs a master switch corresponding to the master clock to send a synchronization message to a first switch; the master switch sends the synchronization message to first switch; the first switch sends the synchronization message and receiving time to the controller; the controller resolves the synchronization message to obtain transmission time, acquires link delay between the first switch and the master switch, calculates a phase offset according to the transmission time, the receiving time and the link delay, calculates a frequency offset according to the transmission time and the receiving time, transmits the phase offset and the frequency offset to the first switch, and instructs the first switch to forward the synchronization message to one of other first switches in the SDN; and the first switches receive the phase offset and the frequency offset, perform clock synchronization, and forward the synchronization message. Through adoption of the clock synchronization method and system, synchronization of an SDN clock can be realized.

Description

technical field [0001] The present invention relates to the technical field of communication, in particular to a clock synchronization method and system. Background technique [0002] With the rapid development of the information age, SDN (Software Defined Network) has become a new type of network with good development prospects due to its strong programmability and infrastructure virtualization. The basis for SDN to complete information exchange and transmission is that the clocks of each device in the network are synchronized with each other. Among them, SDN is generally composed of controllers and switches. [0003] The common clock synchronization method in the prior art, the 1588 clock synchronization method, requires each switch in the network to independently complete the selection of the best master clock in the network, clock synchronization with the master clock, and time service to downstream clock devices. That is to say, each switch has the function of control...

AI Technical Summary

Problems solved by technology

[0004] However, in SDN, the switch is only responsible for forwarding data and has no control function

Therefore, the SDN switch cannot independently complete the functions of selecting the master clock, synchronizing with the master clock, and serving time to the downstream clock device.

Based on the above situation, the traditional 1588 clock synchronization method is not suitable for SDN

Images