Specifications

12E/2FE Port Adapter LEDs

PA-12E/2FE Ethernet Switch 10BASE-T and 100BASE-TX Port Adapter Installation and Configuration

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When using store-and-forward packet switching technology, the 12E/2FE port adapter receives and

processes a packet completely (calculates the cyclic redundancy check [CRC] and checks the

packet’s destination address) before forwarding the packet through the outgoing interface; packets

are temporarily stored until the outgoing interface is available. Store-and-forward packet switching

is the default for the 12E/2FE port adapter.

When using cut-through packet switching technology, the 12E/2FE port adapter reads, processes,

and forwards a packet as soon as the packet’s destination address is looked up and the outgoing

interface is determined. While cut-through packet switching technology greatly reduces the amount

of time a packet spends in the 12E/2FE port adapter—the leading edge of the packet exits the output

interface before the packet ﬁnishes entering the input interface—it enables the 12E/2FE port adapter

to forward packets before calculating the CRC.

All 12E/2FE interfaces (port 0 through port 13) support autosensing and autonegotiation of the

proper transmission mode (half-duplex or full-duplex) with an attached device. The ﬁrst two

12E/2FE interfaces (port 0 and port 1) also support autosensing and autonegotiation of the proper

connection speed (10-Mbps or 100-Mbps) with an attached device.

Each 12E/2FE interface connector is an RJ-45 receptacle that supports standard straight-through and

crossover Category 3 or Category 5 UTP cables. Cisco Systems does not supply Category 3 and

Category 5 UTP cables; these cables are available commercially.

The Cisco 7200 series routers and the Cisco uBR7246 support the online insertion and removal

(OIR) of all port adapter types. OIR functionality allows you to install and replace port adapters

while the router is operating; you do not need to notify the software or shut down the system power.

12E/2FE Port Adapter LEDs

The 12E/2FE port adapter has an enabled LED, standard on all port adapters, and two status LEDs

for each port. (See Figure 1-2.)

Figure 1-2 LEDs on the 12E/2FE Port Adapter (Horizontal Orientation Shown)

After system initialization, the enabled LED goes on to indicate that the port adapter has been

enabled for operation.

The following conditions must be met before the 12E/2FE port adapter is enabled:

• The port adapter is correctly connected to the midplane and receiving power.

• A valid system software image for the port adapter has been downloaded successfully.

• The system recognizes the port adapter.

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