Carrier Access Access Navigator, User Manual

Page: 518 / 704

18-62 August 2003 Access Navigator - Release 1.8
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 ...
Figure 18-3. Send DS1 CSU Line Loopup
DS1
Line
Interface
Unit
Framer
Access Navigator
Time Slot
Interchange
Code
Generator
CSU
Loopup
Command
Inband
Code
IN
OUT
CSU
Access Bank
Far End
Line Loopup