Patent ID: 8000251

Claim:
A method performed by a packet switching device for determining packet delays by the packet switching device, the packet switching device including a plurality of ingress interfaces configured to perform operations including receiving packets from sources external to the packet switching device, a plurality of egress interfaces configured to perform operations including transmitting packets to destinations external to the packet switching device, and a switching mechanism configured to perform operations including switching packets received on the plurality of ingress interfaces to egress interfaces of the plurality of egress interfaces, the method comprising: generating one or more successions of time values; for each particular packet of a plurality of packets: routing the particular packet to a destination egress interface of the plurality of egress interfaces and transmitting from the destination egress interface the particular packet; and identifying at one or more positions other than said ingress and egress interfaces within the packet switching device a current time value of said time values and tangibly storing, in one or more computer-readable media, one or more representations based on one or more packet switching device latencies within the packet switching device for the particular packet determined using the current time value.