HCD-E1 Installation & Operation Manual Chapter 1 - Introduction
01/01/01 08:07 Functional Description 1-7
The transmission of data on each twisted-wire pair (HDSL line) is full duplex,
and except for the distribution of payload data bits between the two lines,
each HDSL line operates independently.
HCD-E1 provides an embedded operations channel (eoc) within the HDSL
data streams, which enables end-to-end system management and
supervision.
The HDSL subsystem operates in a master-slave mode.
The master unit, called line termination unit (LTU), determines the
distribution of payload data between the HDSL lines, controls the system
start-up procedure, provides the timing reference for HDSL line
transmission, and manages the communication on the eoc channel.
The slave unit, located at the remote end of the link, is called network
termination unit (NTU).
HCD-E1 supports both the central (LTU) and the remote (NTU) operating
modes; the actual operating mode (LTU or NTU) is user-selectable.
Note
If you have a phantom-fed H-RPT on the HDSL link, your HCD-E1 must be
used as NTU only.
Management Local Control
HCD-E1 is designed for unattended operation. HCD-E1 configuration, that
is, the complete collection of its operating parameters, is determined by a
database stored in non-volatile memory. The database parameters and the
operation of HCD-E1 can be controlled by means of a simple menu,
operated by push buttons located on the front panel. During setup, the
LCD display guides the operator in the execution of the desired operations.
The display provides information concerning the current system
configuration and operating mode, and the available values of each
programmable parameter. In case of operator errors, HCD-E1 displays the
configuration error number, which helps the operator take the correct
action.
Remote Management
In addition to front panel control, HCD-E1 supports management from a
remote location. The remote management capabilities can be used to
configure the HCD-E1 parameters and display status (alarm) messages,
diagnostics information, performance monitoring data, and the test status.
These functions are performed through a serial RS-232 port that enables
serial communication with a supervision terminal.
Using the supervision terminal functions, the user can also enable remote
management using IP communications, i.e., Telnet and SNMP. The IP
communication uses the Serial Link Internet Protocol (SLIP).