Automatic setting of time-to-live fields for packets in an ad hoc network

• US 6,985,476 B1
• Filed: 08/20/2001
• Issued: 01/10/2006
• Est. Priority Date: 08/20/2001
• Status: Expired due to Fees

• Current Assignee: Raytheon BBN Technologies Corp. (Rtx Corporation)
• Original Assignee: BBNT Solutions LLC (Rtx Corporation)
• Inventors: Pearson, David Spencer, Elliott, Brig Barnum
• Primary Examiner(s): MARCELO, MELVIN C
• Application Number:
  US09/933,380
• Time in Patent Office: 1,604 Days
• Field of Search: 370/311, 370/328, 370/338, 370/345, 370/349, 370/401, 370/474
• US Class Current: 370/349
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 45/20 Hop count for routing purposes, e.g. TTL
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/286 Time to live
• CPC Class Codes: H04L 47/32 by discarding or delaying data units, e.g. packets or frames

Abstract

The present invention helps increase the reliability, throughput, and ease-of-configuration for data networks. The invention sets “time-to-live” (“TTL”) values for packets which may be routed through a network within a router based on a selected route, rather than by a host computer or using a fixed pre-configured value. Upon receiving an incoming data packet from a host computer, a TTL value is set which tailored to network conditions and the route selected. The data packet is then routed within the network using the tailored TTL and is discarded more quickly than if a large default value were used.

Claims

1. A method for routing a plurality of data packets in a network, comprising:

receiving a data packet of the plurality having a destination;

determining a route for the data packet based on the destination;

determining a lifetime for the data packet based on the route;

setting a time-to-live value for the data packet based on the lifetime; and

forwarding the data packet along the route.

2. The method according to claim 1, further comprising:

detecting an event affecting the route; and

modifying the time-to-live value based on the event.

3. The method according to claim 1, wherein determining the lifetime comprises:

incorporating an error factor based on the route for the data packet.

4. The method according to claim 1, wherein forwarding the data packet comprises:

encapsulating the data packet in a wireless packet format; and

setting the time-to-live value in a field of the wireless packet format.

5. A data packet processing node comprising:

an input to receive a data packet having a destination;

a route processor to determine at least one route for the data packet based on the destination;

a lifetime processor to set a lifetime for the data packet based on the at least one route; and

an output to forward the data packet along the route.

6. The network node according to claim 5, wherein the lifetime processor further comprises:

an event detector to detect an event affecting the at least one route.

7. The network node according to claim 5, wherein the lifetime processor further comprises an error factor processor to determine an error factor to associated with the route.

8. The network node according to claim 5, wherein the output to forward the data packet further comprises a wireless interface to encapsulate the data packet in a wireless packet format.

9. The network node according to claim 8, wherein the wireless interface sets, in a field of the wireless packet format, the time-to-live value based on the lifetime for the data packet.

10. An apparatus comprising:

means for receiving a data packet having a destination;

means for determining a route for the data packet based on the destination;

means for determining a lifetime for the data packet based on the route;

means for setting a time-to-live value for the data packet based on the lifetime; and

means for forwarding the data packet along the route.

11. A computer readable medium capable of configuring a device to perform a method for managing data packets in a network, the method comprising:

receiving a data packet having a destination;

determining a route for the data packet based on the destination;

determining a lifetime for the data packet based on the route;

setting a time-to-live value for the data packet based on the lifetime; and

forwarding the data packet along the route.

12. A network for forwarding a data packet from a source to a destination based on a lifetime for the data packet along a route, said network comprising:

a first node including;

means for receiving, from said source, a data packet having a destination;

means for determining a route for the data packet based on the destination;

means for determining a lifetime for the data packet based on the route;

means for setting a time-to-live value for the data packet based on the lifetime;

means for forwarding the data packet to a second node along the route; and

a second node including

means for receiving, from the first node, the data packet;

means for determining the time-to-live value set for the data packet;

means for modifying the time-to-live value to form a modified time-to-live value;

means for forwarding the data packet based on the modified time-to-live value.

13. The network according to claim 12, wherein:

the first node and the second node are ad-hoc routers.

14. The network according to claim 12, wherein the means for forwarding of the second node forwards the data packet towards the destination along the route, when the modified time-to-live value is greater than 0.

15. The network according to claim 12, wherein the means for forwarding of the second node discards the data packet, when the modified time-to-live value is 0.