Verifying the Installation 59
Table 3-2
770 Router LEDs
LED
What the LED Indicates
RDY
This LED is the Ready indicator. It is green when the router is powered up.
NT1
This LED indicates that the internal NT1 (an ISDN device that provides the basic
functionality of a CSU/DSU in an ISDN environment) in the 770 is active. While
synchronizing with ISDN terminal devices, the LED blinks once per second. When
synchronizing with telco switching equipment, it blinks 5 times per second.
LINE
This LED indicates synchronization between the ISDN S interface and the ISDN
terminal device(s).
LAN
This LED indicates that a frame has been sent or received on the interface in the last
minute.
LAN RXD
This LED signifies that traffic has been received on the Ethernet interface.
LAN TXD
This LED signifies that traffic has been sent from the Ethernet interface.
CH1
This LED is the indicator for the first ISDN B channel. Once a connection has been
established on the first B channel, this LED lights.
CH1 RXD
This LED indicates the receipt of traffic on the first ISDN B channel.
CH1 TXD
This LED indicates the transmission of traffic on the first ISDN B channel.
CH2
This LED is the indicator for the second ISDN B channel. Once a connection has been
established on the first B channel, this LED lights.
CH2 RXD
This LED indicates the receipt of traffic on the second ISDN B channel.
CH2 TXD
This LED indicates the transmission of traffic on the second ISDN B channel.
PH1, PH2
These LEDs are analog POTS (plain old telephone service) ports that are green only
when the attached devices (such as a phone, fax, and so on) are in use.
LINK
Located on the back of the router near the Ethernet interface, this LED indicates physical
connectivity to the Ethernet segment.