Ethernet

Elements of the Ethernet System n physical medium used to carry Ethernet signals between computers n set of medium access control rules embedded in each Ethernet interface n Ethernet frame that consists of a set of bits used to carry data over the system.

Operation of Ethernet n CSMA/CD Protocol n Collisions n Best Effort Data Delivery – High-level network protocols do this by establishing a reliable data transport service

Ethernet Frame and Ethernet Addresses

n address fields n variable size data field - carries 46-1,500 bytes of data n error checking field - checks integrity of the bits in the frame to make sure that the frame has arrived intact

Address Fields n 48-bit addresses n IEEE controls assignment of these addresses n Organizationally Unique Identifiers (OUIs) – 24-bit identifier assigned to each organization that wishes to build Ethernet interfaces – organization creates 48-bit addresses using assigned OUI as the first 24 bits of the address

High-Level Protocols and Ethernet Addresses n High-level protocol software - e.g. TCP/IP protocol suite n Address Resolution Protocol (ARP)

Address Resolution Protocol (ARP) n Resolve physical address