User manual

Wide Bank 28 DS3 - Release 2.4 July 2004 7-23
Diagnostics & Troubleshooting
Testing Low-Speed Interface Operation
DS1 NIU Loopback Using Two Wide Banks
This test is similar to the DS1 NIU Loopback on the previous page but uses two Wide Banks
connected back-to-back. The local Wide Bank allows the test set on low-speed side to send an NIU
loopup across the DS3 connection to test the far end Wide Bank’s DS1 NIU loopup response.
1. On local (near-end) Wide Bank, disable loop detection.
(A:Active)> ds1 1 loopdetect off
2. On far-end Wide Bank, enable loop detection.
(A:Active)> ds1 1 loopdetect on
3. Using the test set on the low-speed side, send an NIU loop code toward the remote Wide Bank
over the DS3.
4. Verify that the test set receives a loopup response.
5. If desired, repeat steps 1 to 4 for the remaining low-speed circuit interfaces.
Figure 7-13 Low-Speed NIU Loopback Using Two Wide Banks
Trans-
ceiver
Selector
M13
Framer
Trans-
ceiver
Relays
LS Card HS Card
Send AIS
Trans-
ceiver
Selector
M13
Framer
Trans-
ceiver
Relays
LS Card HS Card
Toward DS1/E1
DS3
DS3
Loop Detect Disabled
Loop Detect Enabled
Relays
DS1/E1
DS1/E1
Local LS
Far-End LS
Relays
NIU Loop-Up
From Test Set
Local DS3
Far-End DS3
NIU Loop-Up
on DS1