Station-to-station full duplex communication in a token ring local area network

Abstract

Abstract A technique for establishing and maintaining full duplex communication between two stations connected to a token ring network, without physically reconfiguring the station connections or otherwise disturbing the network. In an auto-configuration full duplex mode of operation, each station ascertains whether there are only two active stations on the network and, if so, performs an exchange of frames with the other station to establish full duplex communication. One way to ascertain whether only two stations are active is for each station to transmit periodically a neighbor information frame, which contains the identities of the source station and the source station's nearest upstream neighbor. Once established, full duplex communication can proceed at a greater bandwidth than communication in a token ring network, and without latency delays and distance limitations associated with token ring networks. Periodic checks are made by each station in full duplex communication, to ascertain if the other station is still participating or if any third station has become active. In either case, stations in the auto-configuration mode revert to token ring mode automatically. In a variant form of the invention, stations can operate in a fixed full duplex mode, in which the detection of tokens or third stations are merely reported and do not necessarily result in reversion to the token ring mode.

Inventors

• 👤 Barry A. Spinney
• 👤 Henry S. Yang
• 👤 William R. Hawe

Bibliographic Details