OC-3 delivery unit; timing architecture

A delivery unit that interfaces telecommunications media to a switching matrix, said media operable to transport network data, and said switching matrix operable to switch the network data, comprising:

• at least one termination application module that performs conversions between a network data format associated with said switching matrix and a network data format associated with said media, such that network data may be transported and processed within said delivery unit;
• at least one signal processing application module that performs signal processing on the network data;
• a matrix interface application module that transports the network data to said switching matrix after signal processing and that transports the network data from said switching matrix after switching;
• a bus control module operable to receive source timing signals from a timing source, to derive system timing signals from said source timing signals, and to control transport of said system timing signals and the network data between said application modules;
• buses that transport the network data and said system timing signals between said application modules and said bus control module;
• wherein each said application module has a bus interface that receives network data and said system timing signals on said buses, derives local timing signals from said system timing signals, and uses said local timing signals to format network data outgoing from that application module on said buses;
• and
• wherein each said application module further has a local timebase that receives said local timing signals from said bus interface, and derives additional local timing signals for use by that application module.