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Tests
T1 Tests
076R155-000
SpectraComm 553 Fractional T1 DSU
4-7
Issue 7
Installation and Operation Manual
T1 Remote Test with Self-Test
Remote Test with Self-Test isolates the local DSU from the DTE and checks the DSU internal
circuits, the T1 link, and the remote DSU. The test procedure involves two functions:
•
Remote Test — the local DSU transmits an in-band command to its remote DSU, directing the
remote to loop received signals back onto the network. The DSU sends (and accepts) loopback
activation and de-activation codes as defined by ANSI T1.403.
•
Self-Test — the DSU enables its configurable internal Test Pattern Generator to provide the
signal for the Remote Loop and enables its Test Pattern Checker to verify the signal. The DSU
is isolated from its DTE while the Test Pattern Generator and Checker are enabled.
The Remote Test with Self-Test function can be commanded by means of the terminal interface or
by SNMP control.
Figure 4-7
T1 Remote Test with Self-Test, Network Interface
Figure 4-8
T1 Remote Test with Self Test, Cascade Interface
SC 553 DSU
Remote DSU
DTE
Inter-
face
TPG
TPC
Framer
TX
Driver
Analog
Receiver
Network
Analog
Receiver
TX
Driver
Framer
DTE
Inter-
face
TPG = Test Pattern Generator
TPC = Test Pattern Checker
TX
Driver
Analog
Receiver
Framer
DTE
Interface
TPC
TPC
Framer
TX
Driver
Analog
Receiver
TPG = Test Pattern Generator
TPC = Test Pattern Checker
SC 553 DSU
Network Interface
Cascade Interface
Remote
Device
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