Apparatus and method for implementing nondestructive switch of SDH service

Abstract

The invention discloses an apparatus and method for implementing SDH service nondestructive switch. The method includes: respectively converting the serial data in two routes of transmission lines into paralleling data, buffering in FIFO corresponding to the transmission line after byte alignment; selecting a clock signal of the main transmission line from the clock signals of the two transmission lines, sending the clock signal into the phase-locked loop for processing, and then transmitting to the two FIFO as the clock signal of the reading terminals; recording the address storing the framehead data in the FIFO corresponding to the standby transmission line, and then setting the read pointer of the FIFO corresponding to the standby transmission line as the recorded address and producing alignment identification, upon reading frame head data in the FIFO corresponding to the main transmission line; when switch is required, if there has alignment identification, executing switch upon reading the frame head data. The invention can simultaneously switch clock and data, and ensures no generation of code error or LOF or the like alarms in the switch process.

Description

technical field [0001] The invention relates to the communication field, in particular to a device and a method for realizing SDH (Synchronous Digital Hierarchy) service lossless switching. Background technique [0002] In SDH, in order to improve the reliability of transmission, at least two transmission lines are generally set up, and when one fails, it can be switched to other standby transmission lines. The current switching methods have the following problems: First, during the switching process, if both data and clock are switched, there will be alarms such as bit error or LOF (loss of frame); second, when only data is switched, it can realize No bit error or LOF alarms, but in this case the clock cannot be switched at the same time. Contents of the invention [0003] The technical problem to be solved by the present invention is to provide a device and method for realizing lossless switching of SDH services, which can simultaneously switch clock and data, and ensur...

AI Technical Summary

Problems solved by technology

The current switching methods have the following problems: First, during the switching process, if both data and clock are switched, there will be alarms such as bit error or LOF (loss of frame); second, when only data is switched, it can realize No bit error or LOF alarms, but in this case the clock cannot be switched at the same time

Images