SYNCHRONIZATION OF VODSL FOR DSLAM CONNECTED ONLY TO ETHERNET

摘要

A forwarding unit such as a DSLAM (8) receives (21) Ethernet packets and forwards information therein on digital subscriber lines (27). For forwarding voice information of received Ethernet packets a reference clock signal is generated by a clock device (28) and provided to modems (23) for the digital subscriber lines. The clock device includes an extraction unit (29) for selecting at least one stream of received Ethernet packets, and a clock signal generating unit, configured as an adaptive clock unit (31), for generating a reference clock signal according to arrival times of packet in selected packet stream or streams. The reference clock signal can be provided to time reference units (25) in the modems. The extraction unit can analyze received Ethernet packets to find streams of packets from one destination to one user, the packets of each of the streams carrying real time information belonging to a real time service and then select one or more streams to be used by the adaptive clock unit.