Adtran 4175043L2 Manual Do Utilizador

Chapter 6. Diagnostics

61200659L1-1

MX2800 STS-1 User Manual

6-5

A 

 enables the MX2800 STS-1 to generate a CSU 

loop-up pattern (001001…) towards the T1 CSU attached to the 
selected T1 line for six seconds. After six seconds have elapsed, the 
pattern will cease and incoming network traffic will be passed 
through to the CSU device. If the CSU device responded to the 
CSU loop-up pattern, it will return all data back towards the 
network. A loop-down pattern (0000100001….) will be generated 
towards the CSU for six seconds when 

 is selected.   

A 

 

 enables the MX2800 STS-1 to test the 

local T1 loop to the CSU using the standard QRSS pseudo-random 
bit sequence. When 

 is selected, the 

MX2800 STS-1 will initiate a CSU loopback towards the CSU 
attached to the selected T1 line similar to the 

 test 

above. Six seconds after starting the CSU loop-up pattern, the 
MX2800 STS-1 will cease sending the CSU loop-up pattern and 
begin sending an unframed 511 pattern towards the CSU. If the 
CSU device responded to the CSU loop-up pattern, the
MX2800 STS-1 will check the incoming pattern for errors. 
Additional menu items will appear to show the state of pattern 
synchronization, error count, and a clear error count option (see 
Figure 6-7 on page 6-6). Selecting 

 will cease the 

transmission of the QRSS pattern and start transmission of a loop-
down pattern as previously described.