Method for devices in a network to participate in an end-to-end measurement of latency

摘要

A method of determining the latency of path segments in a communication network that uses multi-bit data packets comprises generating a test packet for use in determining the latency of path segments in the network; transmitting the test packet from a first device coupled to the network; storing in the test packet the time when a preselected bit in the test packet is transmitted from the first device; when the test packet is received by a second device coupled to the network, storing in the second device at least one of (a) the time when a preselected bit in the test packet is received by the second device and (b) the difference between (i) the time when the preselected bit in the test packet is transmitted from the first device and (ii) the time when the test packet is received by the second device.

主权项

1. A method of determining a round trip latency of a network path in a communication network having at least two path segments, that uses multi-bit data packets, said method comprising;
generating a test packet for use in determining the latency of each of said at least 2 path segments in said network path; transmitting said test packet between first and second devices coupled to said network at opposite ends of a first path segment, and then between said second device and a third device coupled to opposite ends of a second path segment; and returning said test packet to said first device by transmitting said test packet between said third and second devices and then between said second and first device; storing in said test packet a transmit time when a first preselected bit in said test packet is transmitted from said first device; when said test packet is received by said second device coupled to said network, storing in said second device the difference between (i) the transmit time when said first preselected bit in said test packet is transmitted from said first device and (ii) a receipt time when a second preselected bit in said test packet is received by said second device; and when said test packet is received by said third device coupled to said network, storing in said third device the difference between (i) the transmit time when said preselected bit in said test packet is transmitted from said first device and (ii) a receipt time when a second preselected bit in said test packet is received by said third device; and determining the round trip latency of the network path when said test packet is returned from the third device to said first device via the same devices traversed by said test packet during transmission from said first device to said third device.