ADTRAN 4200659L1 - Manual (Page 128)

Chapter 6. Diagnostics
6-6 MX2800 STS-1 User Manual 61200659L1-1
Figure 6-7. Diagnostics Menu with BERT Selected
VT BERT
A VT BERT enables the MX2800 STS-1 to perform a “head-to-
head” BERT test towards the STS-1 network. Selecting VT BERT
will replace all incoming T1/E1 traffic for the T1/E1 mapped to the
selected VT with an unframed QRSS pattern towards the network.
When
VT BERT is selected, additional menu items will appear to
show the state of pattern synchronization, cumulative error count,
and a clear error count option. Selecting
D ATA M ODE will cease
QRSS pattern generation and substitution of the incoming data
stream. See Figure 6-8 on page 6-7 for an illustration of this test.
Only one T1 port may engage a CSU L OOPBACK , CSU L OOPBACK
W /B ERT , or a L INE B ERT . If a CSU L OOPBACK , CSU L OOPBACK
W /B ERT , or a L INE B ERT is already active at the time a new CSU
L OOPBACK , CSU L OOPBACK W /B ERT , or L INE B ERT is selected, the
former test will be terminated and the latter test will be engaged.
When in VT BERT mode, only the D ATA M ODE option for the
VT/Port under test may be selected. Selecting any other option will
cause an error message to be displayed.