Abstract: A method and apparatus for estimating relative network proximity between request routing agents and client agents are described herein. In one embodiment, the method includes a proximity estimation unit to send a first number of probe messages to a client agent without waiting to receive a reply message, wherein the proximity estimation unit is to receive a first set of reply messages. The apparatus also including a proximity verification unit coupled with the proximity estimation unit, to send a second number of probe messages to the client agent, and to receive a second set of reply messages.

Abstract: A network of switches that employ aggregation of Registered State Change Notifications (RSCNs) is disclosed. In one embodiment, the network comprises multiple switches coupled together, and multiple node devices each directly-coupled to at least one other switch. Each of the switches preferably provides RSCNs to other switches when a node device state change is detected. Each of the switches receiving the RSCNs preferably combines multiple RSCNs to form aggregated RSCN messages that are then used to notify directly-coupled node devices of state changes. The aggregation preferably occurs over a predetermined interval up to some predetermined limit. The aggregated RSCN message for a given node device preferably includes identifiers of only those node devices that share a common zone membership with the given node device.