Service Manual

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6802800U74-AN
Chapter 13: MTS Troubleshooting
13.1.3.3.4
Site Link
Troubleshooting the Site Link essentially consists of checking the correct operation of each layer in the
order starting with the physical layer.
The physical layer may be configured to be either E1 or X.21. The status bsl command provides
different information for the two interface types.
13.1.3.3.5
X.21 Interface
If the Site Link interface had been configured to use X.21 interface, the information provided by the
status bsl command is as follows:
SC) status bsl
Primary Site Link
State:DOWN
Speed: 0 bps Rear port:X.21
HDLC Statistics:- ----Rx---- ----Tx----
Good frames : 0 0
Overruns | Under-
runs
C Line | I Line
lost
CRC/framing er-
rors
: 0 0
: 0 0
: 0
No buffers avail : 0
Buffer overflows : 0
Aborts : 0
Non octet aligned : 0
X.21 Interface:-
Clock Loss events : 2
I Line Off events : 0
Current Clock
state
Current I Line
state
Current C Line
state
: Failed
: On
: Off
• The Site Link State should be shown as UP, the number of good frames transmitted and received
should be non-zero and incrementing indicating site link traffic. The presence of non-zero data in
other numeric fields may indicate a possible Site Link Problem.