Multi-Tech Systems MVP-2400 IP Phone User Manual


 
Technical Configuration (Digital Voips) MultiVOIP User Guide
150
T1 Parameter Definitions (cont’d)
Field Name Values Description
CAS Protocol
E&M Immed Strt
E&M Wink Start
E&M Wink with
dial tone
FXO Ground Strt
FXO Loop Start
FXS Ground Strt
FXS Loop Start
Channel Associated Signaling
(CAS) is a method of incorporating
telephony signaling info into a T1
voice/data stream. In CAS, the
signaling bits (the A, B, C, and D
bits) are multiplexed into the signal
stream of each T1 channel. (By
contrast, in Common Channel
Signaling (CCS), one channel
handles signaling for all other
channels.) Each CAS protocol
defines the states of the signaling
bits during the various stages of a
call (IDLE, SEIZED, ANSWER,
RING-ON, RING-OFF).
The CAS protocol code allows the
VOIP to interact properly with the
PBX or central-office switch that it
serves. The need to download
CAS protocols arises for only a
small minority of VOIP users, and
only when PBX/switch is found to
be incompatible with standard
protocols.
Match this parameter to the setting
of PBX or central-office switch.