Nortel Networks 1000 - Manual (Page 246)

246 NT5D11 and NT5D14 Lineside T1 Interface cards
Table 96
MMI Tests
Test Number Equipment Tested Test Description
1 Lineside T1 card Local loopback
2 T1 link, Lineside T1 card
and T1 network External loopback
3 CPE device and T1
network Network loopback
Test 1, local loopback, loops the T1 link signaling toward itself at the
backplane connector, and test data is generated and received on all
timeslots. If this test fails, it indicates that the Lineside T1 card is defective.
Figure 45 "MMI Local loopback test" (page 246) demonstrates how the
signaling is looped back toward itself.
Test 2, external loopback, assumes an external loopback is applied to
the T1 link. Test data is generated and received by the Lineside T1 card
on all timeslots. If test 1 passes but test 2 fails, it indicates that the T1
link is defective between the Lineside T1 card and the external loopback
location. If test 1 was not run and test 2 fails, the T1 link or the Lineside T1
card could be defective. To isolate the failure to the T1 link, tests 1 and
2 must be run in tandem.
Figure 46 "MMI External loopback test" (page
246) demonstrates how an external loopback is applied to the T1 link.
Figure 45
MMI Local loopback test
Figure 46
MMI External loopback test
Nortel Communication Server 1000
Circuit Card Reference
NN43001-311 02.06 Standard
27 August 2008
Copyright © 2003-2008 Nortel Networks
.