Patent ID: 9369362
Filing Date: 2016-06-14
CPC Classification: H04L

Claim Text:
1. A method of characterizing a communications path between two communications nodes, the method comprising: determining a packet delay D(1,2,1) for a packet to propagate from a first communications node to a second communications node and back to the first; determining a packet delay D(1,3,1) for a packet to propagate from the first node to a third node and back to the first node; transmitting at least one packet from the first node to propagate through the second and third nodes and return to the first node; time stamping the at least one packet with a first time t1X at which the packet is transmitted by the first node and determining a second time t1R at which the at least one packet returns to the first node; time stamping the at least one packet with times t2R and t2X at which the at least one packet is respectively received and transmitted by the second node; time stamping the at least one packet with times t31:1 and t3X at which the at least one packet is respectively received and transmitted by the third node; determining a packet delay D(2,3) in a direction from the second to the third node, or a packet delay D(3,2) in a direction from the third node to the second node for each of the at least one packet to be equal to (t1R−t1X)−D(1,2,1)/2−D(1,31)/2−(t3 X−t3 R)−(t2X−t2R) if the at least one packet was transmitted from the first node respectively to pass through the second node before passing through the third node, or to pass through the third node before passing through the second node; and using the determined packet delay D(2,3) or D(3,2) as a performance parameter for the packet propagation between the second node and the third node.