ADTRAN MX2800 M13 - Manual (Page 111)

MX2800 M13 Multiplexer User Manual Loopbacks, Section 6
61200290L1-1G 6-5
error count, and a clear error count option. See Figure 6-7 on page 6-5. Selecting Data Mode will cease the
transmission of the QRSS pattern and start transmission of a loop down pattern as previously described.
NOTE
When in CSU Loopback w/BERT, only the Data Mode for the T1 under
test may be selected. Selecting any other option results in an error
message.
Figure 6-7. Loopback Menu with BERT Selected
Line BERT
A Line BERT enables the MX2800 to perform a “head-to-head” BERT test toward the CSU. Selecting Line
BERT replaces all incoming network traffic for the selected T1 with an unframed QRSS pattern toward the
CSU. When Line BERT is selected, additional menu items appear and show the state of pattern synchroni-
zation, cumulative error count, and a clear error count option. Selecting Data Mode ceases QRSS pattern
generation and substitution of the incoming data stream.
NOTE
When in Line BERT mode, only the Data Mode option for the T1 under
test may be selected. Selecting any other option will result in an error
message being displayed.