Chapter 1. Introduction
1-4
HDLC Module User Manual
61200222L1-1
This situation requires 24 HDLC Controllers and, therefore, requires
the HDLC Module.
3. T3 Transporting One or More PRI Circuits
When a T3 circuit is transporting one or more PRI circuits, the HDLC
Module is required to process the PRIs' D Channels.
HDLC MODULE FUNCTIONAL DESCRIPTION
The HDLC Module installs into any available slot in the ATLAS chassis
(Base Unit). The ATLAS Front Panel displays the module status. Addi-
tional status information is available via the terminal menu, accessible
through either a VT-100 terminal connected to the ATLAS Base Unit’s
control port, or via a Telnet session established through the Base Unit’s
Ethernet port. If needed, application software necessary for the HDLC
Module can be downloaded using the terminal menu.
Features
•
Each module provides up to 8.192 Mbps of bandwidth.
•
Each module supports up to 128 bidirectional HDLC channels.
•
For each channel, bandwidth is selectable to be Nx56/64 kbps
(N=1-32).
•
Each channel’s HDLC receiver supports flag sequence detection, bit
destuffing, and CRC-16 validation.
•
Each channel’s HDLC transmitter supports flag sequence generation,
bit stuffing, and CRC-16 generation.
•
Performance information such as the number of frames transmitted
and received is provided on a per channel basis.
•
Errors that occur such as CRC errors and aborted frames are reported
on a per channel basis.
PHYSICAL DESCRIPTION
The HDLC Module provides no external interfaces. Both the network
and customer interfaces are provided on other ATLAS components.
Information is passed to and from the HDLC Module via ATLAS’ internal
bus.
Two general-purpose HDLC Controllers can terminate a PRI from
the T3 as needed, if you are using the ATLAS800
PLUS
.
