29
30
NI STATUS
The Network interface (NI) status is shown in
the middle of the Diagnostics/Statistics screen.
The brackets are empty when the link is oper-
ating normally. In this example, various two or
three-letter messages are displayed within the
brackets, illustrating what you may see if the
Model 2710A is not connected at all or is in a
loss of signal condition. Here are the eight sta-
tus messages.
Excessive zeros [EXZ], i.e., lack of pulses, detected. This condition
may occur if the unit is not connected to the network, in which case the
EXZ is displayed continuously. If EXZ comes on intermittently, there
may be a frame, line code or data rate mismatch between the near and
far-end units.
Receiver Carrier Loss [RCL] occurs when 192 consecutive zeros
have been detected at the network interface. RCL clears when a pulse
is detected.
Frame Bit Error [FE] occurs when there is an error in the framing bit
sequence. This may happen due to a disconnected line, mismatched
framing formats or severe errors in the data stream. This error may
indicate a noisy line or cable condition. This error may indicate a noisy
line or cable connection if the frames appear to be set correctly.
Severe Frame Error [SE] occurs when the framing error exceeds a
certain threshold of errors. This may happen due to a disconnected
line, an extremely noisy connection, or mismatched framing.
Loss of Sync [LOS] occurs when the T1 framer in the unit cannot
synchronize itself to the received data stream. This may happen due to
a disconnected line.
Out of Frame [OOF] occurs when no valid frame structure can be
found. This may happen due to a disconnected line or mismatched
framing or mismatched framing.
Alarm Indication Signal [AIS] indicates that the remote unit or the
central office is sending a Blue Alarm, because it is not receiving a sig-
nal; the alarm is an unframed all-ones signal, mainly used to keep the
line alive and to indicate that it is not receiving any signal. This may
indicate that the local unit is receiving a good signal, but that the trans-
mit link may be broken.
Receive Alarm Indication [RAI] indicates that the local unit is receiv-
ing a Yellow Alarm. This alarm is sent by the remote unit or the central
office when it loses the received signal. This indicates the local unit’s
transmitted signal is not reaching the remote unit.
Rx Level The Model 2710A displays the current received signal
strength in dB. There are four level ranges detected:
+2 to –7.5
-7.5 to –15
-15 to –22.5
< -22.5
Valid Interval Count & Current Interval Time
The Valid Interval Count and Current Interval Time display the
number of valid 15 minute intervals in the last 24 hours and the num-
ber of seconds which have elapsed in the current interval, respectively.
The Valid Interval Count saturates at the count of 96 (96 * 15min = 24
hours), while the Current Interval Time rolls over after 900 counts.
When the counter rolls over, it is reset to zero, and the Interval Counter
is incremented by one if the count is less than 96.
Error Counters
These error counters give a second-by-second snapshot of the
link performance. To clear all counters, press the [Backspace] key. If
your keyboard does not have this key, you can press a two-key combi-
nation to affect the same result: Hold down the [Ctrl] key and then
press the [H] key. This will send to the unit the Ctrl-H character, which
is the same as pressing the [Backspace] key.
ERR SEC:
0
0
Errored Seconds in Current Interval....
UAS SEC:
557
209
Unavailable Seconds
SE SEC:
0
0
Severely Errored Seconds
BE SEC:
0
0
Bursty Errored Seconds
LOF SEC:
0
0
Loss of Frame Error Seconds
Valid Interval Count: [96]
Current Interval Time: [899]
