Communication Profile

Network Discovery


When probing for routing switches, early network discovery techniques typically relied on each routing switch’s configuration port to respond to identification requests to confirm the routing switch’s presence. A request packet was typically dispatched to the configuration port, and a response packet provided confirmation of existence. This same request/response approach was generally used for node identification as well. Dispatching one or more requests to an active link (which might be a node or another routing switch) could produce a response if a node was present and it understood the protocol. The new probing technique involves a shift away from the request/response model. Rather than dispatching a request to some possible physical-path-address on the network, and awaiting a response from a packet receiving/processing/replying entity, a single packet is addressed with a round-trip physical-path-address that will essentially “loop” through a possible routing switch and be returned to the originator with all path-addressing bytes removed along the way out and back. Perhaps the best way to visualize this technique is to think of the SpaceWire routing switch as a “roundabout” intersection with a vehicle (packet) both entering and exiting the roundabout at the same point.