Verilink APS 2000 T1 Line Protection (880-502411-001) Product Manual - Manual (Page 15)

Overview
Verilink APS 2000 User Manual 1-7
Channel Service
Units
Verilink offers two Channel Service Units (CSUs) for use with the T1
protection line application — the SCC 2120 and the TAC 2110. The
SCC 2120 provides node controller functionality in addition to all
of the CSU functionality of the TAC 2110. Each node must have
only one SCC 2120 module.
Connector Interface Modules (CIMs) provide network and DSX-1
equipment (EQUIP) connectivity to the SCC and TAC. The SCC 2120
uses the CIM 2022 APS, and the TAC 2110 uses the CIM 2010 APS.
NOTE: Although the CSUs have additional functions related to
channel distribution, use, and management, only those
functions which are applicable to full T1 line protection
switching will be discussed.
Node Controller
Functions
Each APS 2000 node consists of an SCC 2120 and all the associated
circuit elements it controls. In the case of T1 line protection
switching, all of these circuit elements are CSUs.
The SCC 2120 is typically located in the first slot of the first shelf
of each node, and is also known as the “node controller.” The node
controller provides the operator interface for each node. Using
either the ASCII terminal or SNMP Manager, an operator can access
the modules in the APS 2000 node for T1 network administration
and maintenance. This is illustrated in
Figure 1-3 .
Figure 1-3 SCC Node Controller with Operator Interfaces
CSU Functions The CSU provides T1 circuit termination at the customer premises
and connects the customer’s DSX-1 equipment to the network,
regenerating the data received from the line.
Node
Controller
circuits
CSU
circuits
RS-485 Controller Bus
TAC
2110
Local
ASCII
Terminal
Operator Interface
Other units in nod
RS-232D
SCC 2120
TAC
2110 TAC
2110
RS-485 bus
expansion to
other shelves
in node
SNMP
Network Manager
LAN
(MOM)
SLIP
Ethernet
IP over T1