User manual

Getting Started with the Contivity Extranet Switch 4500
2-16
Figure 2-7 shows the T1 CSU/DSU LEDs. Look at the condition of the LEDs,
then examine the corresponding LED table to better understand the indications.
Figure 2-7. T1 CSU/DSU LEDs
Table 2-8. T1 CSU/DSU LED Indicators
LED Description
LED1, Yellow Yellow alarm LED is lit when the far-end equipment is in the red
alarm condition.
LED2, Blue Blue alarm LED is lit when receiving an upstream failure denoted
by an alarm indication signal (AIS).
LED3, Green Normal operation.
LED4, Red Red alarm is lit when a loss-of-signal (LOS) or out-of-frame
(OOF) condition is detected on the receive signal.
LED 4, Red
LED 3, Green
LED 1, Yellow
LED 2, Blue