Token ring simulation : Using opnet

[deverahul2003]

Hello everyone , Here today we will discuss about token ring simulation step by step.

1st: LEARNING:
Token Ring network can be summarized by the following steps:

• Active monitor node: generates the token and supervise it, being sure that won’t be lost. If the token is lost, the monitor will generate another token.
• Token: is continuously circulated on the ring passing through each node. When a node has a message to send, it brings the rights to send holding the token, modifying it by inserting the PDU in the specific field and then transmit.
• The frame will be read by each node in the ring.
• When a node identifies itself being the destination for the message it brings the data and sends back the token with the acknowledgement bit set to “1â€.
• The source node receiving the acknowledgment removes the already sent PDU
• from the send queue.
• If the Timer Holding Token is not expired another frame can be sent. This timer
• is useful to ensure fairness.
• When the token is no more needed both for timer expiration or empty queue
• cases, it is released and starts again to circulate, ready to be used by another
• node.