Input/Output Driven Router Design
What initiates a routing decision?
Packet arrival -- input driven
Availability of output channel -- output driven
Chaos Router was the first to use an output driven protocol
When a packet arrives, find a productive output channel.
When an output channel becomes free, find a packet that can use it. Randomize if more than one.
Many routing algorithms can be implemented using either input or output driven protocols, but output driven is better