COMSPHERE 3600 Series Data Service Units
4-32 March 1999 3610-A2-GB41-60
•Case 4 – Backing up (up to) three channels at
each tributary via the FEP port-sharing feature
(Figure 4-25). In this case, each tributary DSU to
be backed up must be equipped with a DBM and
the MCMP Backup configuration option should be
set to TDM. At the central site, a DSU-DBM-TDM
or DSU-DBM-MCMP unit operating in TDM mode
must be available for each tributary to be backed
up.
Using the FEP port-sharing feature, three channels
from the control DSU-MCMP can be daisy chained
to a set of DSU-DBM-TDM units to provide dial
backup for each tributary DSU. To daisy chain
these units, alternate TDM and digital bridge
interface cables for non-modular devices, and use
crossover cables with modular devices. Essentially,
the backup becomes the dial backup of a set of
point-to-point TDM circuits.
Figure 4-25. Case 4 – Backing Up (Up to) Three Channels via the FEP Port-Sharing Feature