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Hardware Installation Guide for the Cisco 4000 Series  Integrated Services Router
OL-32185-02
Chapter 1      Overview of Cisco 4000 Series ISRs
  Hardware Features of Cisco 4000 Series ISRs
S Speed of Ethernet 
ports 0 and 1
Green
Blinking
Blink frequency indicates port speed:
• 1 blink - 10-Mbps link speed
• 2 blinks - 100-Mbps link speed
• 3 blinks - 1000-Mbps link speed
I/O side All models
Off No link or a non-Ethernet 802.3af/t capable device is 
plugged in and powered over the PoE.
SFP EN Port 0, and 1 (for 
Cisco 4331 ISR), 
and Port 0 for 
Cisco 4321 ISR) 
Enable
Green SFP module is detected and recognized. I/O side All models
Amber Initialized with error.
Off Not present.
SFP S Status of port 0, 
and 1 (for 
Cisco 4331 ISR), 
and Port 0 for 
Cisco 4321 ISR)
Green SFP module is detected and recognized. I/O side All models
Amber Initialized with error.
Off Not present.
Off Not present.
SER CON
(right)
Serial Console 
Active
Green Active console port is RJ-45. 
Note When this LED is on, the USB CON LED 
will be off.
I/O side
2
All models
USB CON
(left)
USB Console 
Active
Green Active console port is USB. 
Note When this LED is on, the SER CON LED 
will be off.
I/O side
2
All models
SSD
mSATA Slot Status Green SSD mSATA is present and enabled. Bezel side All 
models.
Amber Initialized with error.
Off Not present.
POE0
POE PSU Green PoE is on and provides power. Bezel side All 
models.
Amber PoE is in a failed condition.
Off PoE supply is not present.
ISC ISC Slot Status Green PVDM4 is present and enabled. Bezel side All models
Amber Initialized with error.
Off Not present.
FLASH System Flash 
Status
Blinking 
Green 
Compact flash/eUSB flash is present and currently 
being accessed. 
Note Do not remove the flash device while the 
system is powered on.
Bezel side All models
LED Represents Color Description Location
Available 
On