124CHAPTER 4: CONFIGURING PATHBUILDER S330/S310 MODULES, PORTS, AND APPLICATIONS
Structured Voice — Structured service provides N x 64 kbit/second capability, where N ranges between 1 and the maximum number of available DS0 channels. Structured voice service passes traffic with signaling information enabled—it provides for DS0 midspan carrier access with A & B signaling bits terminating DS1 or E1 framing at the CBR T1-DSX or CBR E1 interface.
In structured voice mode, you can build either structured voice or structured data virtual circuits.
Unstructured — Unstructured service provides T1-DSX or E1 frame tunneling; it allows the application to utilize the entire available bandwidth at a bit rate of 1.544 (T1) or 2 (E1) Mbps. T1-DSX framing is optional in this service mode.
Framing—The type of frame organization configured for the T1-DSX or E1 port interface: D4 or ESF for the CBR T1-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)—The trunk condition signaling type: PLAR, E&M/PLAR, FXS, FXO, FXS-GroundStart, or FXO-GroundStart. 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.
For PRI signaling, you must set the TC Signaling Type to PLAR when the port is configured for structured voice.
TC1 Signaling Bits / TC2 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. For further details about trunk conditioning, see “DS0 Trunk Conditioning” later in this section.
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—SRTSfor 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-DSX port is used for the network/carrier service termination, in which case the carrier (the service “loop”) typically provides the timing source.
SRTS (unstructured ports 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.
Adaptive (unstructured ports only)—A non-required network-wide synchronization technique used to regenerate the input service clock. Adaptive timing uses a buffer depth indicator at the receiver to adjust the line rate: the fuller the buffer, the faster the line rate; the emptier the buffer, the slower the line rate.
