Logical Ring Topology
General Notes
![Picture](/uploads/6/5/7/7/65776519/696737624.gif)
- When a logical ring topology is used each node receives frames from one and only one node and transmits the frames to one and only one node. As a consequence all frames circulate a logical ring.
- Typically FDDI, SONET or Token Ring technology are used to implement a ring network.
- FDDI and SONET are both used for long distance communication. In these cases the nodes are routers rather than computers. These examples and most others, a physical ring topology is used in conjunction with logical ring topologies.
- Ring networks are most commonly wired in a star configuration.
- Token Ring has Multi Station Access Unit (MSAU), equivalent to a hub or switch. The MSAU performs the token circulation internally.
How does it work?
- When a node wishes to send it must wait for the token.
- It then attaches its data to the token and sends it on its way.
- The frame containing the data continues around the ring being received and transmitted in turn by each node until it reaches the recipient.
- The recipient takes a copy of the data and also sends the frame onto the next node.
- Eventually the data frame returns to the original sender.
- The sender removes the data frame and sends out the token.
- The token continues to circulate until the next node wishes to send.
aDVANTAGES AND DISADVANTAGES OF logical Ring TOPOlogy
aDVANTAGES
|
dISADVANTAGES
|