Virtual inline configuration for a network device

• US 20070248090A1
• Filed: 04/25/2006
• Published: 10/25/2007
• Est. Priority Date: 04/25/2006
• Status: Active Grant

• Current Assignee: Citrix Systems, Inc. (Cloud Software Group)
• Original Assignee: Orbital Data Corporation (Cloud Software Group)
• Inventors: Budhani, Haseeb, Sutter, Paul
• Granted Patent: US 8,004,973 B2
• Time in Patent Office: Days
• US Class Current: 370/392
• CPC Class Codes: H04L 12/56 Packet switching systems
• CPC Class Codes: H04L 67/563 Data redirection of data network streams

Abstract

A performance enhancing proxy network device is configured to operate in a virtual inline mode, in which selected network traffic is redirected to and through the network device by a router using simple routing policies. In this way, the network device can be coupled to the router in series but can still operate as if it were physically connected inline.

Claims

1. A method for delivering an incoming packet through a performance enhancing proxy network device to a recipient computing system, the performance enhancing proxy network device coupled in a parallel configuration, the method comprising:

receiving a data packet having a destination IP address, the destination IP address specifying a recipient computing system on a local network;

diverting the data packet to the performance enhancing proxy network device;

receiving the data packet from the performance enhancing proxy network device, the data packet processed by the performance enhancing proxy network device; and

sending the data packet to the recipient computing system over the local network.

2. The method of claim 1, wherein the diverting is performed according to a set of policy based routing rules.

3. The method of claim 2, wherein the policy based routing rules are defined at a WAN side of a router.

4. The method of claim 2, wherein the policy based routing rules specify diverting a data packet based at least in part on whether the data packet is a TCP packet.

5. The method of claim 2, wherein the policy based routing rules specify diverting a data packet based at least in part on the data packet'"'"'s source IP address or destination IP address.

6. The method of claim 1, wherein the data packet'"'"'s destination IP address is preserved.

7. A method for sending an outgoing packet through a performance enhancing proxy network device to a destination computing system, the performance enhancing proxy network device coupled in a parallel configuration, the method comprising:

receiving a data packet having a destination IP address, the destination IP address specifying a remote destination computing system over a network;

diverting the data packet to the performance enhancing proxy network device;

receiving the data packet from the performance enhancing proxy network device, the data packet processed by the performance enhancing proxy network device; and

sending the data packet to the destination computing system over the network.

8. The method of claim 7, wherein the diverting is performed according to a set of policy based routing rules.

9. The method of claim 8, wherein the policy based routing rules are defined at a LAN side of a router.

10. The method of claim 8, wherein the policy based routing rules specify diverting a data packet based at least in part on whether the data packet is a TCP packet.

11. The method of claim 8, wherein the policy based routing rules specify diverting a data packet based at least in part on the data packet'"'"'s source IP address or destination IP address.

12. The method of claim 7, wherein the data packet'"'"'s destination IP address is preserved.

13. A method for handling incoming and outgoing data packets in one or more routers, the method comprising:

receiving incoming data packets from a wide area network (WAN), at least some of the incoming data packets having a destination IP address specifying a computing system on a local area network;

receiving outgoing data packets from the local area network (LAN), at least some of the outgoing data packets have a destination IP address specifying a computing system over the wide area network;

diverting the incoming data packets and the outgoing data packets to a network device according to a set of rules;

receiving the diverted data packets from the network device, the diverted data packets retaining their destination IP addresses; and

delivering the diverted data packets according to their destination addresses.

14. The method of claim 13, wherein the incoming data packets are diverted according to a first set of policy based routing rules, and the outgoing packets are diverted according to a second set of policy based routing rules.

15. The method of claim 14, wherein the first set of policy based routing rules is symmetrical and reversed to the second set of policy based routing rules.

16. The method of claim 14, wherein the first and second sets of policy based routing rules are configured to divert only TCP data packets.

17. The method of claim 14, wherein the first and second sets of policy based routing rules are configured to divert only data packets having a source or destination IP address within a predetermined range.

18. The method of claim 13, wherein the incoming and outgoing data packets are received in one of a plurality of routers.

19. The method of claim 18, wherein each diverted data packet is received by the same router that originally diverted the data packet to the network device.

20. A network system for handling incoming and outgoing packets, the system comprising:

a local area network coupled to one or more local computing systems;

a connection to a wide area network;

a performance enhancing proxy network device coupled in parallel to the local area network, the performance enhancing proxy network device configured to receive data packets, perform one or more enhancement processing functions on the data packets, and return the processed data packets to the router; and

a router providing a communication interface between the local area network and the wide area network, wherein the router includes a means for redirecting incoming and outgoing data packets from the local area network and the connection to the wide area network to the performance enhancing proxy network device.

21. The system of claim 20, wherein the means for redirecting preserves a destination IP address of the diverted data packets.

22. The system of claim 20, wherein the means for redirecting is configured to redirect only TCP data packets.

23. The system of claim 20, wherein the means for redirecting is configured to redirect only data packets having a source or destination address within a predetermined range.

24. The system of claim 20, further comprising a plurality of routers providing a communication interface between the local area network and the wide area network, each router including a means for redirecting incoming and outgoing data packets between computing systems on the local area network and the connection to the wide area network.

25. The system of claim 24, wherein the performance enhancing proxy network device is configured to return each redirected data packet to the router that originally redirected the data packet.

26. The system of claim 20, further comprising a plurality of performance enhancing proxy network devices coupled in parallel to the local area network.

27. The system of claim 26, wherein each router'"'"'s means for redirecting sends the data packets to a virtual address, and a primary one of the performance enhancing proxy network devices is configured to receive data packets sent to the virtual address.

28. The system of claim 27, wherein a second performance enhancing proxy network device is configured to receive data packets sent to the virtual address upon failure of the primary performance enhancing proxy network device.