Token Ring (token ring) – architecture of networks with logical ring topology and deterministic access method token-passing. The standard defines the document IEEE802.5, but IBM – the main conductor of this architecture – uses a slightly different specification.

A logical ring implemented in a physical star, in the centre of which is MAU (Multistation Access Unit) hub ports connect each node. To attach cables using special connectors, ensure that the circuit rings when you disconnect the node from the network. If necessary, the network can expand by using additional hubs, related to the overall ring. The requirement complicates petrasiunas ring cable Token Ring farm, use four-wire shielded and unshielded twisted pairs and special switching means.

 Light wiring connects to 96 stations to 12 vosmik hubs with maximum removal of the station from the hub no more 45 m. The cable length between hubs can reach 45 m and their total length not over 120m.

Fixed wiring provides connection to 260 stations and 33 hubs the distance between devices to 100 m with a total length of the ring to the hub 200 m.

Fiber optic cable increases the length of the segment to 1 km.

Information is transmitted around the ring in only one direction along the chain from station to station, transfer rate 4 or 16 MB / with. The host adapter copies in the buffer only the packets addressed to it.

The use of system resources and the PC configuring the Ethernet adapters is similar. The software is also familiar to all the network adapters contains additional modules-the agents on the server, and on the workstation.

The main advantage of Token Ring - deliberately limited the waiting time for a service node (unlike Ethernet is not increasing with increased traffic), due to the deterministic method of access and the ability to control priority.This property allows the use of Token Ring in real-time systems. In addition, Token Ring networks are easy to connect with networks on large machines (IBM Mainframe).

The Disadvantages Of Token Ring is the high cost of equipment and the complexity of building large networks (WAN).