Specifications

Installation and Operation Manual Chapter 1 Overview
DXC-100PSX Functional Description 1-15
2. Redundant broadband module set (if in standby mode) receives configuration
and crossconnect map information for the defective module from the
DXC-100 system manager.
3. PSX controller module receives command from the DXC-100 system manager
to transfer the broadband link (including all embedded T1/E1 links) to the
redundant module in place of the failed broadband module set.
4. Redundant module will synchronize with the link and user traffic will be
re-established.
See
1 Figure 1-12 for an overview of the protection operation where a fault is
detected with the BB2 related DXC-100 module set located in slot 4 (BB1 group
unaffected).
Once the original fault has been cleared or the defective module(s) replaced, the
operator can command the DXC-100/PSX to restore the normal path (i.e.,
revertive restoration is not an automatic process by design).
Due to the N+1 nature of this module sparing scheme (versus 1+1 dedicated
redundancy) this switchover requires a few seconds to complete in a worse case
situation. The only situation that may go beyond this normal range is if the
broadband module set ceases communications to the system manager via the
supervisor channel. The capability to perform a commanded switchover for
maintenance or upgrade purposes in less than 50 milliseconds is available.
DXC-100
Figure 1-12. Broadband Protection Operation
See 1 Table 1-5 for a summary of typical total switchover times for different
scenarios as measured on external test sets (i.e., total disruption time observed
for given switchover criteria).