Administrator's Guide

Glossary and abbreviations
555-233-5061994 Issue 5 October 2002
SBA
Simulated bridged appearance
SCC
1. See single-carrier cabinet.
2. Serial communications controller
SCD
Switch-control driver
SCI
Switch communications interface
SCO
System control office
SCOTCH
Switch Conferencing for TDM Bus in Concentration Highway
SCSI
See small computer system interface (SCSI).
SDDN
Software-Defined Data Network
SDI
Switched Digital International
SDLC
Synchronous data-link control
SDN
Software-defined network
SFRL
Single-frequency return loss
SID
Station-identification number
simplex system
A system that has no redundant hardware.
simulated bridged appearance
The same as a temporary bridged appearance; allows the terminal user (usually the principal) to bridge onto a
call that had been answered by another party on his or her behalf.
single-carrier cabinet
A combined cabinet and carrier unit that contains one carrier. See also Multicarrier cabinet.
single-line voice terminal
A voice terminal served by a single-line tip and ring circuit (models 500, 2500, 7101A, 7103A).
SIT
Special-information tones
SLS
Service Level Supervisor