3Com 3C63100-AC-C - PathBuilder S600 Bridge/router Reference Manual page 161

Structured Data—Structured service provides N x 64 kbit/second
capability, where N ranges between 1 and the maximum number of
available DSO channels. Structured data service passes traffic with signalling
information disabled—it provides for DSO midspan carrier access without A
& B signalling bits terminating DS1 or E1 framing at the CBR DSX or CBR E1
interface.
Structured Voice—Structured service provides N x 56 kbit/second
capability, where N ranges between 1 and the maximum number of
available DSO channels. Structured voice service passes traffic with
signalling information enabled—it provides for DSO midspan carrier access
with A & B signalling bits terminating DS1 or E1 framing at the CBR DSX or
CBR E1 interface.
Unstructured—Unstructured service provides DS1 or E1 frame tunneling; it
allows the application to utilize the entire available bandwidth at a bit rate
of 1.544 Mb/second. T1 framing is optional in this service mode.
Framing—The type of frame organization configured for the DS1 or E1 port
interface: D4 or ESF for the CBR DSX module; G.704 for the CBR E1 module.
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.
TC Signaling Type (Structured Voice mode only)—This is the type of
signaling done between PBXs. This also sets the signalling type used for each of
the virtual circuits across this port. The values for TC Signaling are 1=PLAR,
2=E&M, 3=FXO-Loop Start, 4=FXS-Loop Start, 5=FXO-Ground Start,
6=FXS-Ground Start, 7=R2(E1)
For PRI signalling, you must set the TC Signaling Type to PLAR.
TC Signaling Bits (Structured Voice mode only)—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.
Timing—The type of input clock service configured for the port interface. The
default is System. The SRTS and Adaptive options are normally used for voice
applications—SRTS for unstructured voice applications and Adaptive for
structured voice applications.
System—Configures the port interface to use the internal clock as the
timing source.
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
T1 port is used for the network/carrier service termination, in which case the
carrier (the service "loop") typically provides the timing source.
SRTS (Unstructured mode only)—Synchronous Residual Time Stamp; a
means to measure the service clock frequency against a network-wide
synchronization signal. SRTS measures input frequency against the master
network clock source and adjusts the line rate by sending residual time
stamps in the AAL1 header to the remote end.
Configuring the CBR DSX (or E1) Modules 161