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Node initialization and token bus initialization

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• Node initialization
  • Node initialization:

    When a node first powers up: The node is not a member of the token bus network !!!

    Observation:

    A starting node will not know: The token bus network has be started already In this case, the starting node must join the existing token bus network There is no token bus network running In this case, the starting node must initiate the token bus network

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  • Node initialization protocol of the token bus network:

    When a node is powered up: The node will listens on the token bus for a time out period If the node hears a transmission within given time out period: The node will wait for a Solicit_successor message to insert itself into the token bus network If the node does not hear a transmission within given time out period: The node will execute the token bus initialization protocol (Discussed next)

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• Token Ring initialization
  • The token ring initialization protocol:

    (Executed when a node is powered up and does not hear any transmission for Bus-Idle Timer period) Transmit the Claim_token control frame; if ( no collision ) { Node = token holder Invite other nodes to join token bus network; } else { /* ===================================== Multiple nodes try to claim token... ===================================== */ Execute the collision resolution protocol; if ( winner == true ) { Node = token holder Invite other nodes to join token bus network; } else { Wait for Solicit_successor control frame to join; } }