Patent ID: 8484388

Claim:
A data transmission method, comprising: obtaining a current queue length of a queue corresponding to an output port; when the current queue length meets a back-pressure requirement, determining a back-pressure priority corresponding to the current queue length according to the current queue length and a mapping relationship between a preset queue length and the back-pressure priority, and generating back-pressure information, wherein the back-pressure information inhibits a line card to send data with a data priority less than or equal to the back-pressure priority to the output port; wherein the mapping relationship between the preset queue length and the back-pressure priority is a mapping relationship between the preset queue length and the back-pressure priority or a mapping relationship between a queue length interval and the back-pressure priority; and sending the back-pressure information to a line card to prevent the card from sending the data with the data priority less than or equal to the back-pressure priority to the output port after receiving the back-pressure information; wherein if the mapping relationship between the preset queue length and the back-pressure priority is the mapping relationship between the queue length value and the back-pressure priority, the determining the back-pressure priority corresponding to the current queue length comprises: querying the mapping relationship, and obtaining a back-pressure priority corresponding to a value of the current queue length; and if the mapping relationship between the preset queue length and the back-pressure priority is the mapping relationship between the queue length interval and the back-pressure priority, the determining the back-pressure priority corresponding to the current queue length comprises: querying the mapping relationship, and obtaining a back-pressure priority corresponding to a queue length interval where the current queue length resides.