Paradyne 317x E1 manual Selecting the Timing Source, Common Clocking Configurations

Operation

Selecting the Timing Source

The E1 DSU/CSU provides the ability to select a primary clock (timing) source that is used to synchronize all of the E1 and data port interfaces on the E1 DSU/CSU. The clock for each interface is at the appropriate rate for that interface (e.g., 2.048 Mbps for the E1 interfaces, the configured port rate for the data ports) and is independent of the primary clock rate. This means that the primary clock rate and the E1 DSU/CSU interface rates may be different.

The E1 DSU/CSU automatically falls back to the secondary clock when a failure of the selected primary clock is detected. If a secondary clock failure is detected, the E1 DSU/CSU falls back to its internal clock.

The clock source configuration options enable you to select either the Network E1 interface, a synchronous data port, the internal clock, the DTE Drop/Insert interface, or an external clock. If external clocking is selected, you must use the clock rate configuration option to specify the clock rate. Figure 3-12 shows 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.

3160/3164	3160/3164
	NETWORK
CLOCK: NETWORK	CLOCK: NETWORK
3160/3164	3160/3164

CLOCK: INTERNAL			CLOCK: NETWORK
		3160/3164
	3160/3164

CLOCK: EXTERNAL	CLOCK: NETWORK
3160/3164	3160/3164
PBX
CLOCK: DTE (DSX-1 CONNECTOR)	CLOCK: NETWORK
3160/3164	3160/3164
TERMINAL
EQUIPMENT
CLOCK: PORT 1	CLOCK: NETWORK
	496-14341a-01

Figure 3-12. Common Clocking Configurations

3170-A2-GB20-20 December 1996 3-33