Chapter 7. Test Menu61202156L2-1 TDU 120e User Manual 7-5After a R EMOTE L OOPBACK option is selected, the TDU120e verifies that the far end is actually in a loopback bychecking for the receipt of a code looped back from the farend.Once the R EMOTE L OOPBACK type is selected, the terminaldisplays the loopback progress by displaying L OOPINGuntil loopback is verified.Test PatternsAll OnesSends an all ones pattern to the network.All ZerosSends an all zeros pattern to the network.QRSS PatternThe QRSS pattern is commonly used to simulate realdata in T1 interfaces. This pattern can be assigned toappear in all DS0s or only in TST DS0S. When QRSS isset in all DS0s and one of the network loopbacks previ-ously described is activated at the far end, a total end-to-end integrity check can be run without the need for anyexternal test equipment.When QRSS is assigned to TST DS0 S, an integrity checkof the link can be run along with normal data flow. TheTST DS0S are user assigned as part of the DS0 Map.This sets the pattern for the test and initiates the trans-mission of the pattern. The test is terminated by selectingN ONE.The following patterns are available:QRSS All DS0sGenerates a QRSS test pattern and inserts the pattern intoall DS0s.
