Network Architectures

Ethernet

• Baseband signaling.
• Linear or star-bus topology.
• Usually transmits at 10 Mbps with 100 Mbps possible.
• Uses CSMA/CD for traffic regulation.
• IEEE specification 802.3.
• Uses thicknet, thinnet or UTP cabling
• Media is passive => it draws power from the computer

Ethernet Frames

Ethernet breaks data into frames. A frame can be from 64 to 1,518 bytes long in total. The ethernet frame itself takes up 18 bytes, so the actual data can be from 46 to 1,500 bytes.

• Preamble: marks the start of a frame.
• Destination and Source: addressing information.
• Type: Identifies network layer protocol.
• CRC: error checking data.