Patent ID: 8634297
Filing Date: 2014-01-21
Classification: H04L

Abstract:
1. A method comprising: at a switch configured for communication in a layer-2 multipath network, determining user flow parameters from packets of a user flow that is to be carried through the layer-2 multipath network; encapsulating by the switch the packets of the user flow into frames for transport to a destination switch in the layer-2 multipath network in accordance with one or more network protocols that enforce next hop addresses to be determined from the user flow parameters stored in packet header fields of the respective packets encapsulated by the frames; determining a number of hops that forward the frames from the switch to the destination switch in accordance with the network protocols; generating one or more probe packets having packet header fields matching the packet header fields of the user flow packets and storing therein flow parameters matching the user flow parameters; encapsulating the probe packets into the frames so that the encapsulated probe packets traverse the path carrying the user flow; storing the determined hop count in a hop count header field of the frame encapsulating the one or more probe packets to distinguish the encapsulated probe packets from the encapsulated user flow packets; configuring the switch to timestamp time-to-live expiry packets received from the destination switch, and causing the destination switch to timestamp time-to-live expiry packets received from the switch; sending the encapsulated probe packets through the layer-2 multipath network from the switch; timestamping time-to-live expiry packets received at the switch and causing timestamping of time-to-live expiry packets received at the destination switch in response to sending the encapsulated probe packets; measuring latency between the switch and the destination switch from timestamps in the timestamped time-to-live expiry packets generated at the destination switch and timestamps in the timestamped time-to-live expiry packets generated at the switch; and determining connectivity between the switch and the destination switch based on a response by the layer-2 multipath network to the sending of encapsulated probe packets.