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Line Code — The zero code suppression technique configured to the VCM
T1/E1port. Set this parameter to match the service provider or device connection
line coding. The Line Code must match at local and remote ports.
AMI — Alternate mark inversion; a carrier line coding format whereby
successive ones (marks) are alternately inverted.
B8ZS (T1-DSX only) — Binary 8 Zero Substitution; a T1 (1.544Mbps) carrier line
coding format used to accommodate "ones density" for clear channel
transmission.
HDB3 (E1 only) — High Density Bipolar 3; an E1 carrier line coding format. To
transmit data and maintain synchronization, E0 transmitters use HDB3
encoding to replace runs of four consecutive zeros.
Framing — The type of frame organization configured for the T1-DSX or E1 port
interface: D4 or ESF for VCM T1-DSX; No Multiframe or Multiframe for VCM E1.
Set this parameter to match the service provider or device connection framing. The
Framing must match at local and remote ports.
CAUTION: A framing mismatch can cause LOF, OOF alarm conditions and result in
traffic loss.
Signaling — The signaling type configured for the VCM T1/E1 port: CAS (channel
associated signaling) or CCS (common channel signaling).
The TC Signaling Type, TC1 Signaling Bits, and TC2 Signaling Bits parameters are
applicable only when Signaling is set to CAS.
TC Signaling Type — The trunk condition signaling type: PLAR, E&M/PLAR,
FXO-Loop Start, FXS-Loop Start, FXO-Ground Start, FXS-Ground Start, or R2-E1.
This is the type of signaling done between PBXs. This also sets the signaling type
used for each of the virtual circuits across this port.
TC1 Signaling Bits / TC2 Signaling Bits — Trunk condition 1 and trunk
condition 2 signaling bits: onhook or offhook. The default for TC1 Signaling Bits is
onhook, while the default for TC2 Signaling is offhook. The default values are
usually suitable for PBX applications, but for channel bank applications you should
set TC2 Signaling Bits to onhook. For further details about trunk conditioning, see
"DS0 Trunk Conditioning" earlier in this chapter.
Timing — The type of input clock service configured for the port interface. The
default is System.
System — Configures the VCM port interface to use the system clock as
defined in the System Clock Configuration menu as its timing source. For
details about designating the system clock, see "Configuring the System
Clock" in Chapter 3.
Loop — Configures the port interface to use the input port Rx clock as the
timing source; timing is received from the service "loop." Select Loop if the
VCM T1/E1 port is used for the network/carrier service termination, in which
case the carrier (the service "loop") typically provides the timing source.
CRC (E1 only) — Enables (With CRC multiframe) or disables (No CRC multiframe)
Cyclic Redundancy Check (CRC) information. CRC is a framing option that checks
for errors in data. It is a communication check for parity/framing and is used for
performance monitoring in E1 networks.
Admin Status — Administrative status: Out of Service or In Service.
Configuring the Voice Compression Module
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