Synchronization of VoDSL of DSLAM connected only to ethernet

摘要

A packet forwarding unit such as a Digital Subscriber Line Access Multiplexer (DSLAM) receives Ethernet packets carrying real-time information and forwards the information therein on output lines such as Asymmetric Digital Subscriber Lines (ADSLs). The DSLAM includes a clock device having an extraction unit and an adaptive clock. The extraction unit analyzes received packets to select streams of received packets from one destination to one user, and the adaptive clock generates a reference clock signal according to the arrival times of packets in the selected streams. The clock signal is sent to time reference units in DSL modems for the output lines.