DSU Operations
4-17
3610-A2-GB91-90
July 1999
Loopback
The Loopback (Lpbk) selection displays four loopback
tests:
•
Local Loopback (LL)
•
DTE Loopback (DTE)
•
Digital Loopback (DL)
•
Remote Digital Loopback (RL)
Local Loopback
Local Loopback (LL) is session-disruptive and permits
the DTE to run a test to determine whether the DTE
connection to the DSU and the DSU itself is functioning
properly. The DSU must be connected to the DTE. The
network connection to the DSU is not required.
Local Loopback is used with the DTE test after the
DSU passes a Device Test.
To access Local Loopback from the top-level menu,
make the following selections:
•
Local (F1)
•
Test
•
DSU
•
Lpbk
•
LL
While the DSU is in Local Loopback, any data
transmission by the DTE is returned as received data
(Figure 4-4). An operator can send a test pattern and
verify correct reception of the test. The DSU does not
monitor this testing.
NOTE
When a Local Loopback is
requested of an inactive core,
there is no effect since the data
from the DTE port is routed
through the active core.
F1
DSU Local Lpbk:
Command Complete
F2
F3
NOTE
When Nondisruptive Diagnostics
is enabled (Diag Type = NonD),
Local Loopback disrupts
secondary channel transport
communications. For a control
DSU, the DSU will report No
Response or Tributary Timeout
during the test.
Figure 4-4. Local Loopback
Summary of Contents for COMSPHERE 3610
Page 4: ...COMSPHERE 3600 Series Data Service Units C July 1999 3610 A2 GB91 90 Notices ...
Page 16: ...COMSPHERE 3600 Series Data Service Units x July 1999 3610 A2 GB91 90 ...
Page 27: ...Introduction 1 11 3610 A2 GB91 90 July 1999 Figure 1 4 NMS Interfaces to the SDU 1 of 2 ...
Page 128: ...COMSPHERE 3600 Series Data Service Units 5 6 July 1999 3610 A2 GB91 90 ...
Page 186: ...COMSPHERE 3600 Series Data Service Units 6 58 July 1999 3610 A2 GB91 90 ...
Page 187: ...A 1 3610 A2 GB91 90 July 1999 Data Service Unit Menu A ...
Page 188: ...COMSPHERE 3600 Series Data Service Units A 2 July 1999 3610 A2 GB91 90 ...
Page 189: ...Data Service Unit Menu A 3 3610 A2 GB91 90 July 1999 ...
Page 190: ...COMSPHERE 3600 Series Data Service Units A 4 July 1999 3610 A2 GB91 90 ...
Page 224: ...COMSPHERE 3600 Series Data Service Units C 22 July 1999 3610 A2 GB91 90 ...
Page 259: ...Pin Assignments F 11 3610 A2 GB91 90 July 1999 Figure F 8 EIA 232 D Crossover Cable 4951 035F ...
Page 272: ...COMSPHERE 3600 Series Data Service Units H 6 July 1999 3610 A2 GB91 90 ...
Page 278: ...COMSPHERE 3600 Series Data Service Units I 6 July 1999 3610 A2 GB91 90 ...
Page 280: ...COMSPHERE 3600 Series Data Service Units J 2 July 1999 3610 A2 GB91 90 ...
Page 292: ...COMSPHERE 3600 Series Data Service Units L 10 July 1999 3610 A2 GB91 90 ...