Cisco Systems 1721 See the section “OK LED Diagnostics” in Chapter, LED Label, Color, Description

Chapter 1 Cisco 1721 Router Overview

Front Panel LEDs

Figure 1-3 Front Panel LEDs

PWR	WIC0 WIC1	ETH
	ACT/CH0 ACT/CH0	ACT
OK	ACT/CH1 ACT/CH1	COL

65537

Table 1-4 Front Panel LEDs

LED Label	Color	Description
PWR	Green	On means that DC power is being supplied to the router.
OK	Green	On means that the router has successfully booted up and the software is
		functional. This LED blinks during the power-on self-test (POST).
		See the section “OK LED Diagnostics” in Chapter 3,
		“Troubleshooting,” for information on how to use this LED for router
		diagnostics.
WIC0
ACT/CH0	Green	Serial and DSU/CSU cards—Blinks when data is being sent to or
		received from the port on the card in the WIC0 slot.
		ISDN cards—On solid when the first ISDN B channel is up for the card
		in the WIC0 slot.
		2-port serial cards—Blinks when data is being sent to or received from
		the first port on the 2-port card in the WIC0 slot.
ACT/CH1	Green	Serial and CSU/DSU cards—Remains off.
		ISDN cards—On solid when the second ISDN B channel is up for the
		card in the WIC0 slot
		2-port serial cards—Blinks when data is being sent to or received from
		the second port on the 2-port card in the WIC0 slot.

	Cisco 1721 Router Hardware Installation Guide
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