Patent attributes
Embodiments relate to optical transport technologies, and more specifically, to a clock transmission method. Under this method, a first optical data unit (ODU) container can be obtained. Phase discrimination can be performed on an obtained first clock and a first ODU clock of a transmit end, to generate a first PD value. The first PD value can then be inserted into an overhead of the first ODU container. The first ODU container can be encapsulated into a second ODU container, and the second ODU container can be sent. A rate of the second ODU container is higher than a rate of the first ODU container. The first PD value is transmitted in the first ODU container which is not decapsulated in a subsequent transmission process. Therefore, final recovery of the first clock is not affected, so that a deviation between a finally recovered clock and the first clock is greatly reduced.