Processes of Link-State Protocols
The link-state protocols consist of four processes: Receive process
The received information is processed, and then is given to the update process. The receive process does not make decisions—it simply forwards information to the two other processes.
Update process
Receives information from the receive process, processes the information received from all the neighbors, and creates information about the local router states. The update process is responsible for processing LSPs from the neighbors and creating the routers' own LSPs, maintaining the link-state database.
Decision process
The optimal path to the destination is found by running the SPF algorithm. The decision process also computes parallel paths to the destination.
Forwarding process
The information received from the receive process, as well as the information received from the routing process is passed along. If a local router is using that information in its routing process, any information that the local router is not using is also processed by the forwarding process. In link-state protocols, all information that a local router has must still be forwarded to all the neighbors, even if the local router is not using that information in its own routing information database.
The received information is processed, and then is given to the update process. The receive process does not make decisions—it simply forwards information to the two other processes.
Update process
Receives information from the receive process, processes the information received from all the neighbors, and creates information about the local router states. The update process is responsible for processing LSPs from the neighbors and creating the routers' own LSPs, maintaining the link-state database.
Decision process
The optimal path to the destination is found by running the SPF algorithm. The decision process also computes parallel paths to the destination.
Forwarding process
The information received from the receive process, as well as the information received from the routing process is passed along. If a local router is using that information in its routing process, any information that the local router is not using is also processed by the forwarding process. In link-state protocols, all information that a local router has must still be forwarded to all the neighbors, even if the local router is not using that information in its own routing information database.
