Optical transport network delay measurement

摘要

In one embodiment, a one-way delay is measured between optical devices in an optical transport network based on roundtrip times of request and corresponding response frames. A first optical device sends a sequence of delay measurement request frames to a second optical device, which varies a local delay before responding to a request frame, thus causing a slippage in the sequence of reply frames received by the first device. The point at which the request frames are received in relation to the stream of frames sent by the optical device can be identified based on the frame slippage. Therefore, the delay measurement can be adjusted by a corresponding offset to the beginning of a frame in order to increase the accuracy of the one-way delay measurement.

主权项

1. A method, comprising:
sending, from a first optical device towards a second optical device over an optical transport network, a sequence of request frames includes a plurality of request frames; receiving, by the second optical device, each frame of the sequence of request frames; for each particular request frame of the sequence of request frames, sending, by the second optical device towards the first optical device over the optical transport network, a particular response frame after imposing a variable delay after receiving said particular request frame and before adding a delay measurement marker to a frame to create the particular response frame; receiving, by the first optical device, each said particular response frame; and processing different pairs of corresponding said request frames and said response frames to calculate a one-way delay measurement between the first optical device and the second optical device; wherein said processing different pairs includes identifying a frame slip within said received response frames, and adjusting the one-way delay measurement by an offset value determined based on said identified frame slip within said received response frames.