Method to accurately and securely determine propagation delay and distance between sending and receiving node in packet network using cut-through approach and packet network node for executing the method

• US 8,879,564 B2
• Filed: 05/30/2011
• Issued: 11/04/2014
• Est. Priority Date: 02/11/2006
• Status: Expired due to Fees

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Ryu, Hyun Surk, Garner, Geoffrey M., Den Hollander, Cornelis Johannis, Feng, Fei Fei, Jung, Kyu Hong
• Primary Examiner(s): VU, HOANG-CHUONG Q
• Application Number:
  US13/118,514
• Publication Number:
  US 20110243145A1
• Time in Patent Office: 1,254 Days
• Field of Search: 370/252, 370/389, 370/392, 370/395.42, 370/400, 370/410, 370/412, 370/428, 370/429, 370/519, 709227-229, 709/238, 726/4, 726 26- 30
• US Class Current: 370/400
• CPC Class Codes: H04J 3/0682 by delay compensation, e.g. by compensation of propagation delay or variations thereof, by ranging
• CPC Class Codes: H04L 43/0864 Round trip delays
• CPC Class Codes: H04L 43/10 Active monitoring, e.g. heartbeat, ping or trace-route

Abstract

A method and system for measuring a distance between nodes in a packet network are provided. The system and method include measuring and storing a departure time of a ping packet sent from a source node to a destination node, sending a response packet with respect to the ping packet from the destination node to the source node, cutting through the ping packet or response packet to a successive node or the destination node without an intermediate node delay, computing a round-trip time by measuring an arrival time of the response packet at the source node and measuring the distance between the nodes, based on the round-trip time and speed of the ping packet.

Claims

1. A method of processing a packet in a dedicated unit included in a node of a packet network, the method comprising:

receiving a packet at the node in the packet network;

determining a packet kind of the packet received at the node; and

prioritizing the packet at the node, based on the packet kind, wherein the prioritizing comprises;

in response to the packet not being destined for the node, assigning pre-emptive priority to the packet, suspending transmission of another packet that has been partially transmitted, and transmitting the pre-emptive priority packet,

in response to the packet being a ping packet destined for the node, changing a field of the ping packet and sending the packet as a response packet; and

in response to the packet being a response packet destined for the node, computing a round-trip time of the packet.

2. The method of claim 1, wherein the prioritizing of the packet at the node based on the packet kind comprises preventing a delay of the packet at the node and sending the packet to a successive node, in response to the packet not being destined for the node.

3. The method of claim 2, wherein the preventing of the delay of the packet at the node and sending the packet to a successive node comprises:

storing the other packet that is in the process of being transmitted;

transmitting the packet to the successive node or a destination node; and

resuming transmission of the stored other packet after the transmission of the packet is completed.

4. The method of claim 1, wherein the prioritizing of the packet at the node, based on the packet kind comprises;

changing the field of the packet; and

sending the packet to a source node from which the packet originated.

5. The method of claim 4, wherein the sending of the packet to the source node comprises:

changing a destination address of the packet into an address of the source node;

changing a packet type identifier included in the packet from a ping type into a response type; and

sending the ping packet to the source node, as the response packet.

6. The method of claim 5, further comprising authenticating the packet by the node wherein the packet responds to the authentication of the node by using a security key shared with the packet network.

7. The method of claim 1, wherein the prioritizing the packet at the node, based on the packet kind comprises determining a distance based on the round-trip time, in response to the packet kind being a response packet destined for the node.

8. The method of claim 7, wherein the determining of the distance comprises:

determining an arrival time of the packet at the node;

determining a departure time of the packet from the node;

computing the round-trip time by using a difference between the arrival time and the departure time; and

determining the distance based on the round-trip time and speed of the packet.

9. The method of claim 1, wherein the node is an intermediate node, and the prioritizing comprises assigning pre-emptive priority to both a ping packet that is not destined for the node and also assigning pre-emptive priority to a response packet that is not destined for the node to reduce a round-trip transmission of the ping packet and the response packet between a source node and a destination node.