Unit 5

Lesson 1 - LAN Data Link Protocols

   The IEEE 802 Suite of LAN Protocols

In the mid-1980s, the new LAN protocols were brought into the standards-making process of the Institute of Electrical and Electronics Engineers (IEEE), where they have been continually refined and documented by working groups of network professionals. The IEEE 802 standards committee produced the 802 suite of LAN standards, illustrated on the IEEE 802 Suite Diagram, which has been adopted by the International Standards Organization (ISO) as OSI standard 8802.



IEEE 802 Suite

IEEE 802 Suite

The IEEE 802 suite of LAN protocols includes:

802.1--Abstract definitions of interactions between LAN
services.

802.2 LLC--Standards for Data Link frame addressing and error checking.

802.3 Carrier sense multiple access with collision detection (CSMA/CD)--A MAC standard used in Ethernet networks. (Ethernet and CSMA/CD are explained in detail in the next lesson.) Further extensions to 802.3 describe the Ethernet cabling standards 10Base2, 10Base5, 10BaseT, and 100BaseT.

802.4 Token Bus--A MAC standard that uses token passing on a bus topology. (Token passing is explained in detail in a later lesson.)

802.5 Token Ring--A MAC standard that uses token passing on a pure ring or star ring topology.

802.6 Distributed Queue Dual Bus (DQDB)--A MAC protocol for switched metropolitan area networks (MANs).

802.11 Wireless LANs--The Physical Layer and MAC protocols for radio communication, using carrier sense multiple access with collision avoidance (CSMA/CA). (Wireless LANs are explained in detail in a later lesson.)

802.12 100VG-AnyLAN--A 100-megabits-per-second (Mbps) standard that uses demand priority media access as its MAC method. It is currently overshadowed by its direct competitor, Ethernet (802.3), thus we will not discuss it in this course.

   Activities

See the Activities and Extended Activities section in Unit 5 Lesson 1 in your textbook Introduction to Networking to test what you have learned so far.

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