Token Ring Formed in May of 1992, the Token Ring Consortium examined the Physical and Media Access Control layers of the IEEE 802.5 Token Ring Protocol. Physical layer testing focused on the measurement of accumulated jitter which V.J. Shah described in his University of New Hampshire master's thesis Reliable Measurements of Clock Jitter in Token Ring Local Area Networks.
The Token Ring Consortium tested MAC and PHY-layer conformance for the majority of its life. Additionally, during its mid-1990s Dedicated Token Ring phase, the laboratory tested interoperability of devices for most of the major players in the industry, several of which identified interoperability issues that were resolved via recommended changes to the standard itself.
Originally, Token Ring emerged alongside Ethernet as an advanced network protocol vying for dominance in larger networks in, for example, government agencies and banking. While at the time Ethernet moved data at speeds of 10 megabits per second, Token Ring came out of the gate running at 4 Mb/sec but promising 16. However, Token Ring's real advantage over Ethernet was fault tolerance. In earlier Ethernet networks, when a device in the hub failed, it brought the entire network down. Token Ring was the first networking protocol that enabled engineers to know that a device had failed, even as the rest of the network stayed up and running. Thus, Token Ring occupies an important moment in the history of networking where the network first became smart enough to tolerate a weak link in its chain which is precisely what has allowed data networks to scale to where they are today.
Over its lifetime, the Token-Ring consortium served more than 40 member companies. Token Ring was eventually superseded by advances in Ethernet and network management protocols. The end of Token-Ring chipset production combined with the changed focus of many of the prominent Token-Ring equipment manufacturers brought about the close of the Token Ring Consortium in January 2001. Please contact us if you have any questions about this or any other consortium or technology. |
Additionally, the consortium produced the industry's first Token Ring signal generator and receiver (shown at right). Building upon hardware and software that the laboratory had developed for testing Ethernet standards-conformance, the consortium built the first test tool that could generate and receive signals with sufficient granularity to fully control and analyze individual frames within a data transmission.