Method, system and article for router-assisted fast processing of packet termination in hosts

• US 20050100010A1
• Filed: 11/06/2003
• Published: 05/12/2005
• Est. Priority Date: 11/06/2003
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Venkatsubra, Venkat, Jain, Vinit
• Granted Patent: US 7,876,757 B2
• Time in Patent Office: Days
• US Class Current: 370/389
• 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 69/16 Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]
• CPC Class Codes: H04L 69/161 Implementation details of TCP/IP or UDP/IP stack architecture; Specification of modified or new header fields

Abstract

A last router in the route of a packet determines when a packet is at the last hop prior to reaching its destination, based on information conveyed in the routing table that the destination is a directly-connected host, and can then convey that information to the host by setting the TTL to zero in the packet being forwarded to its final destination. The host, being so informed that the packet is destined for its IP address, can thereby eliminate the IP address table search for the destination IP address of the incoming packet against the list of its allocated IP addresses to determine if the packet is destined for that host, thereby providing significant performance enhancements to the network system by enabling a receiving host to skip the IP address lookup process and immediately consume the received packet.

Claims

1. A method in a data processing system (router) for assisting network packet processing in a data processing system (destination host), said method comprising the steps of:

receiving a data packet at the router over a network;

determining if the destination host for the packet is a next hop from the router;

setting an identifier in the data packet, if the destination host for the packet is a next hop from the router; and

transferring the data packet to the destination host, wherein the identifier is read by the destination host and informs the destination host that it is the destination for the data packet and to bypass a process to determine if the data packet is addressed to the destination host.

2. The method according to claim 1, wherein the step of determining if the destination of the packet is a next hop from the router includes determining if a destination host for the data packet is directly connected to the router or if the destination host is connected to the router through one or more other routers.

3. The method according to claim 1, wherein the identifier is a TTL field in a header of the data packet set to zero.

4. The method according to claim 1, wherein the step of determining includes checking if a flag is set in the router'"'"'s routing table.

5. A method in a data processing system (destination host) for router-assisted network packet processing, said method comprising the steps of:

receiving a data packet from a router at the destination host;

determining if an identifier in the data packet has been set by the router that indicates that the destination host is the destination for the data packet; and

bypassing a process to determine if the data packet is addressed to the destination host, if the identifier in the data packet has been set by the router.

6. The method according to claim 5, wherein the indicator further indicates that the destination host is directly connected to the router.

7. The method according to claim 5, wherein the identifier is a TTL field in a header of the data packet set to zero.

8. The method according to claim 5, further comprising the step of performing a process to determine if the data packet is addressed to the destination host, if the identifier in the data packet has not been set by the router.

9. The method according to claim 8, wherein the process is a destination address lookup within an address table listing destination addresses associated with the destination host.

10. A data processing system (router) for assisting network packet processing in a data processing system (destination host) comprising:

means for receiving a data packet at the router over a network;

means for determining if the destination host for the packet is a next hop from the router;

means for setting an identifier in the data packet, if the destination host for the packet is a next hop from the router; and

means for transferring the data packet to the destination host, wherein the identifier is read by the destination host and informs the destination host that it is the destination for the data packet and to bypass a process to determine if the data packet is addressed to the destination host.

11. The data processing system according to claim 10, wherein the means for determining if the destination of the packet is a next hop from the router includes means for determining if a destination host for the data packet is directly connected to the router or if the destination host is connected to the router through one or more other routers.

12. The data processing system according to claim 10, wherein the identifier is a TTL field in a header of the data packet set to zero.

13. The data processing system according to claim 10, wherein the means for determining includes means for checking if a flag is set in the router'"'"'s routing table.

14. A data processing system (destination host) for router-assisted network packet processing comprising:

means for receiving a data packet from a router at the destination host;

means for determining if an identifier in the data packet has been set by the router that indicates that the destination host is the destination for the data packet; and

means for bypassing a process to determine if the data packet is addressed to the destination host, if the identifier in the data packet has been set by the router.

15. The data processing system according to claim 14, wherein the indicator further indicates that the destination host is directly connected to the router.

16. The data processing system according to claim 14, wherein the identifier is a TTL field in a header of the data packet set to zero.

17. The data processing system according to claim 14, further comprising means for performing a process to determine if the data packet is addressed to the destination host, if the identifier in the data packet has not been set by the router.

18. The data processing system according to claim 17, wherein the process is a destination address lookup within an address table listing destination addresses associated with the destination host.

19. An article of manufacture comprising machine-readable medium including program logic embedded therein that causes control circuitry in a data processing system (router) for assisting network packet processing in a data processing system (destination host) within a network to perform the steps of:

receiving a data packet at the router over a network;

determining if the destination host for the packet is a next hop from the router;

setting an identifier in the data packet, if the destination host for the packet is a next hop from the router; and

transferring the data packet to the destination host, wherein the identifier is read by the destination host and informs the destination host that it is the destination for the data packet and to bypass a process to determine if the data packet is addressed to the destination host.

20. The article of manufacture of claim 19, wherein the step of determining if the destination of the packet is a next hop from the router includes determining if a destination host for the data packet is directly connected to the router or if the destination host is connected to the router through one or more other routers.

21. The article of manufacture of claim 19, wherein the identifier is a TTL field in a header of the data packet set to zero.

22. The article of manufacture of claim 19, wherein the step of determining includes checking if a flag is set in the router'"'"'s routing table.

23. An article of manufacture comprising machine-readable medium including program logic embedded therein that causes control circuitry in a data processing system (destination host) for router-assisted network packet processing within a network to perform the steps of:

receiving a data packet from a router at the destination host;

determining if an identifier in the data packet has been set by the router that indicates that the destination host is the destination for the data packet; and

bypassing a process to determine if the data packet is addressed to the destination host, if the identifier in the data packet has been set by the router.

24. The article of manufacture of claim 23, wherein the indicator further indicates that the destination host is directly connected to the router.

25. The article of manufacture of claim 23, wherein the identifier is a TTL field in a header of the data packet set to zero.

26. The article of manufacture of claim 23, further comprising the step of performing a process to determine if the data packet is addressed to the destination host, if the identifier in the data packet has not been set by the router.

27. The article of manufacture of claim 26, wherein the process is a destination address lookup within an address table listing destination addresses associated with the destination host.