Nortel DMS-100 Series Maintenance Manual page 48

1-32 Maintenance overview
The LCC clock source is frequency-locked to the primary DS-1 links. The
OPAC software controls the LCC clock source with one exception. This
exception occurs when both units of the LCM are inactive. In this condition,
LCM hardware forces each LCM unit to take the clock source from the LCC
of that LCM unit.
Other host office functions
The software of the host DMS-100 Family office controls the following
functions:
Signaling and supervision
Signaling allows the DMS-100 to communicate with the DMS-100 stations
or other switching offices. The OPAC uses DMS-X protocol to
communicate over OPAC DS-1 links with the host office.
The DMS-X is a half-duplex, byte-oriented protocol like DS30. The
DMS-X receives and transmits message data over full-duplex media like the
DS-1 links. The DMS-X is a state-driven code that requires handshake
messaging between the OPAC and host at each data transfer stage.
The byte transfer rate over DS-1 channels is 1.44 Mbyte/s.
Subscriber tones
The host LTC/LGC provides cadenced tones that the OPAC applies as
required to subscriber lines. The host LTC/LGC supports and the OPAC
applies the following tones:
The DMS-100 switch CM has power over the OPAC. The OPAC is not
involved in signaling between the host office and other systems.
297-8211-550 Standard 05.01 August 1999
class of service
code interpretation
screening
routing
billing
dial tone
audible ringing
warble (MBS ringing)
busy tone
reorder tone
receiver off-hook (ROH) tone