PSTN operation and maintenance
(Q.513)
A supervision plan by
network levels:
n Different alarm classes
n Vital functions and circuits
 (as SS7 and group switch)
use secured paths and
backups
Procedures provided for:
n troubleshooting
n fault diagnostics
n hardware faults can
be isolated
n Supervision is realized also
by connecting maintenance
units to the network
n Important switches have
extensive backup equipment