Specifications

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PA-8E 10BaseT Ethernet Port Adapter Installation and Configuration
OL-3494-04
Chapter 1 Overview
Ethernet 10BaseT Overview
The PA-8E can be installed in the following slots on the hardware platforms described in this document:
• VIP (in the Cisco 7000 series and Cisco 7500 series routers)—Port adapter slot 0 and port adapter
slot 1
• Catalyst RSM/VIP2 (in a Catalyst 5000 family switch)—Port adapter slot 0 and port adapter slot 1
• Cisco 7304 PCI Port Adapter Carrier Card (in the Cisco 7304 router)—router module slots 2
through 5
• Cisco 7200 series routers and Cisco 7200 VXR routers—Port adapter slot 1 and slot 2 of the
Cisco 7202 router; port adapter slot 1 through slot 4 of the Cisco 7204 router and Cisco 7204VXR
router; port adapter slot 1 through slot 6 of the router and Cisco 7206VXR router
• Cisco 7100 series routers—Port adapter slot 3 in the Cisco 7120 series router, and port adapter slot 4
in the Cisco 7140 series router
• Cisco uBR7200 series universal broadband routers—Port adapter slot 1 of the Cisco uBR7223
router; port adapter slot 1 and slot 2 of the Cisco uBR7246 router and Cisco uBR7246 VXR router
• Cisco 7201 router—Port adapter slot 1
• Cisco 7301 router—Port adapter slot 1
• Cisco 7401ASR router—Port adapter slot 1
Port adapters have a handle attached, but this handle is not always shown in the figures to allow a full
view of detail on the port adapter faceplate.
Ethernet 10BaseT Overview
The term Ethernet is commonly used for all carrier sense multiple access/collision detect (CSMA/CD)
LANs that generally conform to Ethernet specifications, including IEEE 802.3. Ethernet Version 2 and
IEEE 802.3 were based on and developed shortly after Ethernet Version 1. The slight differences
between Ethernet and IEEE 802.3 are implemented in hardware, and both are supported automatically
by the Ethernet 10BaseT port adapter without any hardware configuration changes. Ethernet and
IEEE 802.3 are the most widely used LAN protocols. They are well suited to applications in which a
local communication medium must carry sporadic, occasionally heavy traffic at high peak data rates.
Stations on a CSMA/CD LAN can access the network at any time. Before sending data, the station listens
to the network to see if it is already in use. If the network is in use, the station waits until the network is
not in use, and then transmits. A collision occurs when two stations listen for network traffic, and do not
hear any, and then transmit simultaneously. When this happens, both transmissions are damaged, and the
stations must retransmit. The stations detect the collision and use backoff algorithms to determine when
they should retransmit.
Both Ethernet and IEEE 802.3 are broadcast networks, which means that all stations see all
transmissions. Each station must examine received frames to determine whether it is the intended
destination. If the destination is correct, it passes the frames to a higher protocol layer for processing.
IEEE 802.3 specifies several different physical layers, and Ethernet defines only one.
Each IEEE 802.3 physical layer protocol has a name that summarizes its characteristics in the format
speed/signaling method/segment length, where speed is the LAN speed in Mbps, signaling method is the
signaling method used (either Baseband or Broadband), and segment length is the maximum length
between stations in hundreds of meters.