Nortel Networks Circuit Card 311 - Manual (Page 255)

Man-Machine T1 maintenance interface software 255
Figure 46
MMI Local loopback test
Figure 47
MMI External loopback test
Test 3, network loopback, loops the received T1 data back toward the CPE
equipment. No test data is generated or received by the Lineside T1 card. If
test 2 passes but test 3 fails, it indicates that the CPE device is defective. If
test 2 was not run and test 3 fails, the T1 link or the CPE device could be
defective. To isolate the failure to the CPE device, tests 2 and 3 must be run
in tandem.
Figure 48 "MMI Network loopback test" (page 255) demonstrates
how the signaling is looped back toward the CPE equipment.
Figure 48
MMI Network loopback test
Nortel Communication Server 1000
Circuit Card Reference
NN43001-311 01.04 Standard
Release 5.0 23 May 2008
Copyright © 2003-2008, Nortel Networks
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