Providing Backup Capability; Selecting The Timing Source - Paradyne 3160-A4 Operator's Manual

4. Configuration

Providing Backup Capability

If the T1 network fails, the DSU/CSU provides the ability to reconfigure the unit
and restore (at least partially) priority data circuits through an external backup
device.
You can store backup configuration options in the Customer 2 set of
customer-defined configuration options. The Enterprise MIB variable
devConfigAreaCopy allows the entire contents of one configuration area to be
copied into another configuration area via SNMP.
By cross-connecting two synchronous data ports to each other, one port can
provide a backup path for the other. As soon as the ports are configured to be
mapped to each other, Data Set Ready (DSR) for the ports is turned on. The
external backup device can be configured to initiate dialing when it detects the
off-to-on transition of DSR.

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.
Common Clocking
Two sample procedures for configuring timing are given in the following sections,
Configuring for Network Timing
on page 4-43. For more information on configuration options, refer to
Configuration Options
4-40
7. From the Clear Channel screen, select NET to clear all DS0 channels
assigned to the network interface. Or, select DTE to clear all DS0 channels
assigned to the DTE Drop/Insert (DSX-1) interface. Or, select a port to clear all
assignments for that data port.
Clear Channel:
NET DTE
F1 F2
Configurations, shows some common clocking configurations.
.
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.
March 2001
Port1
F3
on page 4-42 and Configuring for External Timing
Figure 4-7,
Appendix C,
3160-A2-GB24-10