Specifications

On-Line Operation
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The Excalibur Multirate DAP provides two diagnostic tests (Dial Tone Test and End-to-
End Call Test) that can be initiated only during dedicated line operation. They do not
interrupt the DAP's data transmission during or after the test. Instructions for initiating
these tests are given in the previous section, "Analog Dial Line Tests."
• Dial Tone Test - takes the dial line off-hook and checks for a wink (dial tone).
• End-to-End Call Test - establishes a dial line connection between the local and
remote DAPs. The local DAP then sends a message to verify the end-to-end
connection. The DAP initiating the call must have a functional dedicated line
path to the unit being called.
The Switched 56 IDBU performs all mandatory loop tests initiated by the Switched 56
network. Recommended loop tests are not provided.
ISDN Dial Line Tests
The Excalibur Multirate DAP provides eight diagnostic tests that check the performance
of the dial backup line when the Dial Mode parameter is set to EISDN in the Dial
Configuration submenu. Three of the tests (Dial Tone Test, End-to-End Call Test, and
Self-Error Test) can be initiated only during digital line operation. They do not interrupt
the DAP's data transmission during or after the test. The End-to-End Error Test, Digital
Loop Test, V.54 Digital Loop Test, Loop 2 Test, and Loop 2 Error Test can be initiated
only during dial backup operation and are provided at aggregate, channel, and port levels
to facilitate running tests in mixed multiport and singleport environments. (See "Fault
Isolation Strategy" in Chapter 7 for a description of the each test level.) When the Dial
Mode parameter is set to ISDN in the Dial Configuration submenu, two tests are
available: Dial Tone Test and Self-Error Test.
• Dial Tone Test - checks the line to see if it is ready to receive a call setup.
• End-to-End Call Test - establishes a dial line connection between the local and
remote DAPs. The local DAP then sends a message to verify the end-to-end
connection. This test is only available when the Dial Mode parameter is set to
EISDN.
• Self-Error Test - loops the dial interface back towards the unit and a pseudo-
random 2047 or 511 test pattern is transmitted, received, and checked for errors.
The error count can be monitored and errors can be inserted.
• End-to-End Error Test - local and remote units stop passing main channel data
and transmit and receive a pseudo-random 2047 or 511 test pattern. The error
count from each unit can be monitored and errors can be inserted at each unit.
• Digital Loop Test - isolates the local DTE from the rest of the network. During
this test, the IDBU establishes two loops. It loops its receive data from the line to
its transmitter output, and its transmit data input from the DTE to its receive data
output to the DTE. RTS is looped as DCD.