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076R155-000
SpectraComm 553 Fractional T1 DSU
1-1
Issue 7
Installation and Operation Manual
Chapter 1:
System Description
Overview
The SpectraComm 553 Data Service Unit (SC 553 DSU) is a highly efficient
means of transmitting and receiving digital data. It provides interface between
customer equipment and a T1 or Fractional T1 (FT1) digital carrier facility
provided by a Telco or other carrier. The SC 553 DSU performs both Data Service
Unit (DSU) and Channel Service Unit (CSU) functions.
As a DSU it converts one channel of customer data to bipolar format for
transmission over the T1 network. As a CSU it is responsible for network
interfacing and protection.
The basic SC 553 DSU is a 7-inch by 9.5-inch (178 mm by 241 mm) printed
circuit (pc) card. It conforms to the GDC SpectraComm packaging format for
installation in a variety of housings. The 16-slot, rack-mounted SpectraComm
5000 shelf and the 10-slot, table-mounted MultiPak enclosure are available for
high-density installation at a central site location. The two-slot SpectraComm
2000 enclosure, which can be rack-mounted or wall-mounted, supports remote
site installation.
The SC 553 DSU is software controllable for configuration, diagnostic testing,
and alarm management. Software control takes two forms: Simple Network
Management Protocol (SNMP) control or terminal interface control. Both types
of control can be extended from a master DSU installed at a central site to its
dedicated remote DSU. A SpectraComm Manager (SCM) card has to be installed
with the DSU in an SC 5000 shelf or a MultiPak enclosure at the central site to
provide communication and interface functions. SNMP control, which requires
the use of a computer to serve as an SNMP controller, supports a broader range
network-wide management capabilities. Terminal interface control is limited to
one master DSU and its remote at a time.
An optional 530 Interface Card may be mounted on the SC 553 base card to
support the use of an EIA-530 DTE interface. When the 530 Interface Card is not
installed, the DSU provides an IUT-T V.35 interface. An optional T1 Cascade
Interface Card may be mounted on the SC 553 base card. The card sup-ports a
cascade port that can be selected for either DS1 or DSX-1 operation. The Cascade Interface card
can be used to support drop/insert capabilities for the DSU or to enable the unit to operate as a
channel service unit (CSU) interfacing a DSX-1 signal from the customer site onto the T1 network.
defines part numbers for standard and optional equipment available for the SC 553 DSU.
Appendix A, Technical Characteristics lists its technical characteristics.
553
OOF NS
INS
ON
L
I
N
E
I
N
O
U
T
RSP
SD
RD
EQ
BPV
AIS
TM
ALM
CH
T1
RL
TX
RX
M
O
N