In local area networks (LANs), a non-contentious medium access control
(MAC) convention that allows both the centralized master station, which
commonly is in the form of a server, and each slaved station to
determine the maximum length of time that passes before a station gains
access to the network, perhaps on the basis of programmed access
priorities. Deterministic access employs token passing, a protocol in
which a token, which consists of a specific bit pattern, indicates the
status of the network -- available or unavailable.The token is generated
by a centralized master control station and transmitted across the
network.The station in possession of the token (the last station to
receive the message containing the token) controls the access to the
network. That station may either transmit or require other stations to
respond. Transmission is in the form of a data packet of a predetermined
maximum size, determined by the number of nodes on the ring and the
traffic to be supported. After transmitting, the station passes the
token to a successor station, in a predetermined sequence. Token passing
is complex and overhead-intensive, but the associated high level of
network control avoids data collisions.Token Ring is a deterministic LAN
protocol.
Subscribe to:
Post Comments (Atom)
No comments:
Post a Comment