Cablelength short – Enterasys Networks X-Pedition XSR CLI User Manual
Page 63
T1/E1 & T3/E3 Commands
XSR CLI Reference Guide 2-57
the received signals. This feature is provided by placing a transmit attenuator in the data path.
This attenuation is selectable from 0, ‐7.5, ‐15, or ‐22.5 dB.
Syntax
cablelength long
{0db | -7.5db | -15db | -22.5db}
Syntax of the “no” Form
Use the no form of this command to return the LBO value to the default:
no cablelength long
Defaults
0 dB
Mode
Controller configuration:
XSR(config-controller<xx>)#
Example
The following example sets the long haul LBO to –7.5 dB:
XSR(config)#controller t1 1/0
XSR(config-controller
cablelength short
For T1 controllers only
This command specifies the pulse shape of the transmit signals as defined in the ANSI T1.102
recommendation for short‐haul applications.
These applications apply to haul lengths shorter or equal to 655‘(DSX‐1 interface). This parameter
is used to obtain an optimal pulse shape for external transformers. Five haul length ranges are
defined, each with different pulse shaping settings: 0...133 ft (0..40m), 133..266 ft (40..81m),
266...399 ft (81..122m), 399..533 ft (122..162m), and 533..655 ft (162..200m).
Note: Long haul line build-out (LBO) compensates for the loss in decibels based on the distance
from the device to the first repeater in the circuit. A longer distance from the device to the repeater
requires that the signal strength on the circuit be boosted to compensate for loss over that distance.
The ideal signal strength should be between -15 dB and -22 dB, which is calculated by adding the
Telecom/PTT company loss + cable length loss + line build out. The lengthening or building out of a
line is used to control far-end crosstalk. Line build-out attenuates the stronger signal from the
customer installation transmitter so that the transmitting and receiving signals have similar
amplitudes.
0db
Number of decibels by which the transmit signal is lowered.
-7.5db
Number of decibels by which the transmit signal is lowered.
-15db
Number of decibels by which the transmit signal is lowered.
-22.5db
Number of decibels by which the transmit signal is lowered.