Method, system and article for rapid detection and avoidance of high data corrupting routes within a network

• US 20050036452A1
• Filed: 08/14/2003
• Published: 02/17/2005
• Est. Priority Date: 08/14/2003
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: International Business Machines Corporation
• Inventors: Vallabhaneni, Vasu, Banerjee, Dwip N., Venkatsubra, Venkat, Jain, Vinit
• Granted Patent: US 7,394,769 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04L 1/0061 Error detection codes
• CPC Class Codes: H04L 1/0072 Error control for data other than payload data, e.g. control data
• CPC Class Codes: H04L 1/08 by repeating transmission, e.g. Verdan system H04L1/1858 and H04L1/189 take precedence
• CPC Class Codes: H04L 1/16 in which the return channel carries supervisory signals, e.g. repetition request signals
• CPC Class Codes: H04L 1/1809 Selective-repeat protocols
• 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 45/22 Alternate routing
• CPC Class Codes: H04L 45/28 using route fault recovery
• 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
• CPC Class Codes: H04L 69/163 In-band adaptation of TCP data exchange; In-band control procedures
• CPC Class Codes: H04L 69/22 Parsing or analysis of headers
• CPC Class Codes: H04L 69/40 for recovering from a failure of a protocol instance or entity, e.g. service redundancy protocols, protocol state redundancy or protocol service redirection management of faults, events, alarms or notifications in data switching networks H04L41/06

Abstract

A receiving host in a TCP/IP network sends an acknowledgment indicating a received data packet is corrupt. The sending host will begin transmitting with a new field set in the IP header called a check-TCP-checksum bit, thereby requesting that all routers in the TCP/IP network perform a checksum on the entire received packet. Routers in the TCP/IP network will perform a complete checksum on an entire packet with the check-TCP-checksum bit set, and not just on the IP header. The routers continuously monitor the ratio of corrupt packets received on a particular port that fail the entire packet checksum to the total number of packets received on that port. If the ratio of corrupt-to-received packets exceeds a corruption threshold, the router assumes that the associated link is causing data corruption and issues a routing update indicating that the link is bad and should be avoided. Once the retransmission rate between the sender and receiver drops below a threshold level, the bad link has been detected and avoided within the TCP/IP network and the check-TCP-checksum option in the IP header is no longer set in data packets transmitted to the receiver host.

Claims

1. A method in an IP network for detection and avoidance of data links causing data corruption, said method comprising the steps of:

receiving a data packet over a data link at a router within an IP network, wherein the data packet is sourced by a sender and destined for a receiver and contains an indication to perform a checksum on the entire data packet;

performing a checksum on the entire data packet, in response to receiving the data packet containing the indication to perform the checksum on the entire data packet;

modifying a value indicating the number of data packets received over the data link that failed the checksum, in response to a failure of the checksum of the entire data packet; and

performing a routing update to avoid transmission of data packets over the data link, if the value exceeds a corruption threshold for the router.

2. The method according to claim 1, further comprising the step of sending a packet acknowledgment from the receiver to the sender indicating that a received data packet is corrupt.

3. The method according to claim 1, further comprising the step of, following receipt of a packet acknowledgment from the receiver indicating that a received data packet is corrupt, sending a data packet from the sender to the receiver, wherein the data packet contains an indication that a router receiving the data packet en route to the receiver should check the entire data packet for data corruption.

4. The method according to claim 1, further comprising the steps of determining a retransmission rate of data packets from the sender to the receiver, and sending a data packet from the sender to the receiver, wherein the data packet does not contain an indication that a router receiving the data packet en route to the receiver should check the entire data packet for data corruption, if the retransmission rate is less than a predetermined threshold.

5. The method according to claim 1, further comprising the step of:

(a) receiving a packet acknowledgment from the receiver indicating that a received data packet is corrupt;

(b) following receipt of the packet acknowledgment, sending data packets from the sender to the receiver that contain an indication that a router receiving the data packet en route to the receiver should check the entire data packet for data corruption;

(c) determining a retransmission rate of data packets from the sender to the receiver; and

(d) performing step (b) until it is determined at step (c) that the retransmission rate is less than a predetermined threshold, and thereafter performing step (e);

(e) sending data packets from the sender to the receiver that do not contain an indication that a router receiving the data packets en route to the receiver should check the entire data packets for data corruption.

6. The method according to claim 1, wherein an entire data packet includes the IP header, the TCP header and the data payload of the data packet.

7. The method according to claim 1, wherein the value is stored in a register of the router.

8. The method according to claim 1, wherein the indication is a flag set in the IP header of the data packet.

9. The method according to claim 1, wherein the routing update is performed in conformance with OSPF.

10. The method according to claim 1, wherein the IP network is a TCP/IP network, and wherein the data packet is sourced by a TCP sender and destined for a TCP receiver.

11. A system for detection and avoidance of data links causing data corruption in an IP network, said system comprising:

means for receiving a data packet over a data link at a router within an IP network, wherein the data packet is sourced by a sender and destined for a receiver and contains an indication to perform a checksum on the entire data packet;

means for performing a checksum on the entire data packet, in response to receiving the data packet containing the indication to perform the checksum on the entire data packet;

means for modifying a value indicating the number of data packets received over the data link that failed the checksum, in response to a failure of the checksum of the entire data packet; and

means for performing a routing update to avoid transmission of data packets over the data link, if the value exceeds a corruption threshold for the router.

12. The system according to claim 12, further comprising means for sending a packet acknowledgment from the receiver to the sender indicating that a received data packet is corrupt.

13. The system according to claim 12, further comprising means for, following receipt of a packet acknowledgment from the receiver indicating that a received data packet is corrupt, sending a data packet from the sender to the receiver, wherein the data packet contains an indication that a router receiving the data packet en route to the receiver should check the entire data packet for data corruption.

14. The system according to claim 12, further comprising means for determining a retransmission rate of data packets from the sender to the receiver, and sending a data packet from the sender to the receiver, wherein the data packet does not contain an indication that a router receiving the data packet en route to the receiver should check the entire data packet for data corruption, if the retransmission rate is less than a predetermined threshold.

15. The system according to claim 12, further comprising means for:

(a) receiving a packet acknowledgment from the receiver indicating that a received data packet is corrupt;

(b) following receipt of the packet acknowledgment, sending data packets from the sender to the receiver that contain an indication that a router receiving the data packet en route to the receiver should check the entire data packet for data corruption;

(c) determining a retransmission rate of data packets from the sender to the receiver; and

(d) performing step (b) until it is determined at step (c) that the retransmission rate is less than a predetermined threshold, and thereafter performing step (e);

(e) sending data packets from the sender to the receiver that do not contain an indication that a router receiving the data packets en route to the receiver should check the entire data packets for data corruption.

16. The system according to claim 12, wherein an entire data packet includes the IP header, the TCP header and the data payload of the data packet.

17. The system according to claim 12, wherein the value is stored in a register of the router.

18. The method according to claim 12, wherein the indication is a flag set in the IP header of the data packet.

19. The system according to claim 12, wherein the routing update is performed in conformance with OSPF.

20. The system according to claim 12, wherein the IP network is a TCP/IP network, and wherein the data packet is sourced by a TCP sender and destined for a TCP receiver.

21. An article of manufacture for detection and avoidance of data links causing data corruption in an IP network, comprising machine-readable medium including program logic embedded therein that causes control circuitry in a data processing system to perform the steps of:

receiving a data packet over a data link at a router within an IP network, wherein the data packet is sourced by a sender and destined for a receiver and contains an indication to perform a checksum on the entire data packet;

performing a checksum on the entire data packet, in response to receiving the data packet containing the indication to perform the checksum on the entire data packet;

modifying a value indicating the number of data packets received over the data link that failed the checksum, in response to a failure of the checksum of the entire data packet; and

performing a routing update to avoid transmission of data packets over the data link, if the value exceeds a corruption threshold for the router.

22. The article of manufacture according to claim 21, further comprising the step of sending a packet acknowledgment from the receiver to the sender indicating that a received data packet is corrupt.

23. The article of manufacture according to claim 21, further comprising the step of, following receipt of a packet acknowledgment from the receiver indicating that a received data packet is corrupt, sending a data packet from the sender to the receiver, wherein the data packet contains an indication that a router receiving the data packet en route to the receiver should check the entire data packet for data corruption.

24. The article of manufacture according to claim 21, further comprising the steps of determining a retransmission rate of data packets from the sender to the receiver, and sending a data packet from the sender to the receiver, wherein the data packet does not contain an indication that a router receiving the data packet en route to the receiver should check the entire data packet for data corruption, if the retransmission rate is less than a predetermined threshold.

25. The article of manufacture according to claim 21, further comprising the step of:

(a) receiving a packet acknowledgment from the receiver indicating that a received data packet is corrupt;

(b) following receipt of the packet acknowledgment, sending data packets from the sender to the receiver that contain an indication that a router receiving the data packet en route to the receiver should check the entire data packet for data corruption;

(c) determining a retransmission rate of data packets from the sender to the receiver; and

(d) performing step (b) until it is determined at step (c) that the retransmission rate is less than a predetermined threshold, and thereafter performing step (e);

(e) sending data packets from the sender to the receiver that do not contain an indication that a router receiving the data packets en route to the receiver should check the entire data packets for data corruption.

26. The article of manufacture according to claim 21, wherein an entire data packet includes the IP header, the TCP header and the data payload of the data packet.

27. The article of manufacture according to claim 21, wherein the value is stored in a register of the router.

28. The article of manufacture according to claim 21, wherein the indication is a flag set in the IP header of the data packet.

29. The article of manufacture according to claim 21, wherein routing update is performed in conformance with OSPF.

30. The article of manufacture according to claim 21, wherein the network is a TCP/IP network, and wherein the data packet is sourced by a TCP sender and destined for a TCP receiver.