Token ring
Token ring
Token ring local area network (LAN) technology is a communications protocol for local area networks. It uses a special three-byte frame called a “token” that travels around a logical “ring”of work stations or servers. This token passing is a channel access method providing fair access for all stations, and eliminating the collisions of contention-based access methods.
Comparison with Ethernet
Ethernet and Token ring have some notable differences:
- Token Ring access is more deterministic, compared to Ethernet’s contention-based CSMA/CD
- Ethernet supports a directcable connection between two network interface cards by the use of a crossover cable or through auto-sensing if supported. Token ring does not inherently support this feature and requires additional software and hardware to operateon a direct cable connection setup.
- Token ring eliminate collision by the use of a single-use token and early token and early token release to alleviate the down time. Ethernet alleviates collision by carrier sense multiple access and by the use of an intelligent switch; primitive Ethernet devices like hubs can precipitate collisions due to repeating traffic blindly.