Configuration Options

Table C-6. General Configuration Options (2 of 2)Primary Clock Source: NetworkNetwork DTE Internal External Port 1

Specifies the master clock source for the DSU/CSU. This selection synchronizes all internal timing and external interface clocks. The clock rate(s) for the external timing interfaces are independent of the input rate for the master clock. Failure of the clock specified by the clock source selection results in automatic fallback to internal clock.

Network – Configures the network interface as the master clock source.

DTE – Configures the DTE Drop/Insert (DSX-1) interface as the master clock source. This selection is not available if the DTE Drop/Insert (DSX-1) interface is disabled. If the DTE Drop/Insert (DSX-1) interface is disabled after making this selection, the master clock source is changed to Network.

Internal – Configures the internal clock as the master clock source.

External – Configures an external clock (provided through the Clock In connector) as the master clock source.

Port 1 – Configures Port 1 as the master clock source. This is the only synchronous data port you can use for the master clock. If you enable EDL if for Port 1 and the DSU/CSU Clock Source is set to Port 1, the external device must provide clocking of 8 kbps less than the expected data port rate. For example, if you select 64 kbps, the external clock must supply a 56 kbps clock signal.

External Clock Rate (KHz): 1544 2048 1544 8

Specifies the clock rate when the master clock source is configured for external clock. This configuration option does not appear when the clock source is not an external clock.

2048 – Sets the input rate of the external clock to 2,048 kHz.

1544 – Sets the input rate of the external clock to 1,544 kHz.

8 – Sets the input rate of the external clock to 8 kHz.

NOTE: External clock rate 2,048 kHz does not imply E1 compatibility.

C-16

August 2000

3162-A2-GB20-40