Paradyne 3160-A2-GB21-50 manual Selecting the Timing Source, Common Clocking Configurations

ACCULINK 316x DSU/CSU

Selecting the Timing Source

The DSU/CSU provides the ability to select a master clock (timing) source that is used to synchronize all of the T1 and data port interfaces on the DSU/CSU. The clock for each interface is at the appropriate rate for that interface (e.g., 1.544 Mbps for the T1 interfaces, the configured port rate for the data ports), and it is independent of the master clock rate. This means that the master clock rate and the DSU/CSU interface rates may be different.

The clock source configuration options enable you to select either the network interface, a synchronous data port, the internal clock, the DTE Drop/Insert (DSX-1) interface, or an external clock. If external clocking is selected, you must use the clock rate configuration option to specify the clock rate. Figure 3-11shows some

common clocking configurations. Two sample procedures for configuring timing are given in the following sections, Configuring for Network Timing and Configuring for External Timing. For more information on configuration options, refer to Appendix C.

NOTE

The external clock source is only available for 2-port and 4-port DSU/CSUs. For carrier-mounted DSU/CSUs, the external clock provides timing for up to eight slots in the carrier. Each Auxiliary Backplane must have its own external clock input.

NETWORK

CLOCK: NETWORK CLOCK: NETWORK

CLOCK: INTERNAL CLOCK: NETWORK

CLOCK: EXTERNAL

PBX

CLOCK: DTE (G.703) CONNECTOR

TERMINAL

EQUIPMENT

CLOCK: PORT 1, 2, 3, OR 4

CLOCK: NETWORK

CLOCK: NETWORK

CLOCK: NETWORK

496-14341-03

Figure 3-11. Common Clocking Configurations

3-32 January 1997 3160-A2-GB21-50