Carrier Access Access Navigator user manual Send DS1 CSU Loopup, Line loopback deactivate

CLI Language Reference

CLI Command List

Send DS1 CSU Loopup

NOTE: The DS1 must be set Out of Service, using the set ds1 <n> down command, before you can use loopbacks or test patterns.

NOTE: For normal operation, the loopback must be disabled (loopdown).

NOTE: This command works with ESF or D4 (SF) framing. This command also works with SLC-96/TR-08 framing for Shelves B, C, D. (For Shelf A, use the command Send DS1 Line Loopup on page 18-63.)

Purpose: Sends an in-band(bit pattern) line loopup or loopdown code over the Access Navigator DS1. This is called a “CSU” line loopup to avoid confusion with the out-of-band(FDL) line loopup described in Send DS1 Line Loopup on page 18-63. The CSU loopup is used with other commands and test equipment to verify that the DS1 signal is reaching a far-end Channel Service Unit (CSU), such as the Access Bank II.

CSU loopups can be used with either unframed (line) or framed (payload) patterns and test commands, including Send DS1 Line <pattern>, Send DS1 Line <pattern> Test, Send DS1 Payload <pattern>, and Send DS1 Payload <pattern> Test.

When the operator sends the csu loopup command, the Access Navigator transmits a T1.403 defined in-band line loopback activate code over the drop DS1 to the CSU. After the required 5-second integration time, the CSU should perform a line loopback, which loops the received DS1 frame back to the DS1 transmit output (see Figure 18-3).

When testing is complete, send a csu loopdown command.

NOTE: This command will send one of the following T1.403 defined code words, repeated for 5 seconds.

Line loopback activate:	00001 00001 ...
Line loopback deactivate:	001 001 001 ...

CSU	Access Navigator		Inband		Far End
		Code
Loopup
		Generator	Code	Line Loopup
Command
				Access Bank

Time Slot Interchange

Framer

Line

Interface

Unit

IN

DS1 OUT

CSU

Figure 18-3. Send DS1 CSU Line Loopup

18-62 August 2003 Access Navigator - Release 1.8