Method and apparatus for content-aware web switching

• US 20030065711A1
• Filed: 10/01/2001
• Published: 04/03/2003
• Est. Priority Date: 10/01/2001
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Shaikh, Anees A., Verma, Dinesh C., Acharya, Arup, Tewari, Renu
• Granted Patent: US 7,209,977 B2
• Time in Patent Office: Days
• US Class Current: 709/203
• CPC Class Codes: H04L 45/306 Route determination based on the nature of the carried application
• CPC Class Codes: H04L 61/00 Network arrangements, protocols or services for addressing or naming
• CPC Class Codes: H04L 61/35 involving non-standard use of addresses for implementing network functionalities, e.g. coding subscription information within the address or functional addressing, i.e. assigning an address to a function
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers
• CPC Class Codes: H04L 67/10015 Access to distributed or replicated servers, e.g. using brokers
• CPC Class Codes: H04L 67/1023 based on a hash applied to IP addresses or costs
• CPC Class Codes: H04L 67/14 Session management for real-time applications in data packet communications networks H04L65/1066
• CPC Class Codes: H04L 67/2876 Pairs of inter-processing entities at each side of the network, e.g. split proxies
• CPC Class Codes: H04L 67/561 Adding application-functional data or data for application control, e.g. adding metadata
• CPC Class Codes: H04L 67/564 Enhancement of application control based on intercepted application data
• CPC Class Codes: H04L 67/63 Routing a service request depending on the request content or context
• 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 69/162 involving adaptations of sockets based mechanisms secure socket layer H04L63/168
• CPC Class Codes: H04L 69/163 In-band adaptation of TCP data exchange; In-band control procedures
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]

Abstract

This invention provides methods and apparatus for web switching without connection termination while providing content routing functionality. Content-aware web switches terminate incoming TCP connections and inspect the HTTP header to recognize the URL (content) being requested from a web server farm. This invention maps application layer information (URLs) to MPLS labels. This allows a standard MPLS switch to provide web switching functionality without terminating TCP connections. In addition to content routing, this method is applied for client session affinity, server load balancing and service differentiation. This invention also relates to using TCP port numbers instead of MPLS labels to achieve web-switching functionality through the use of a TCP router that translates IP address and port numbers.

Claims

1. A method comprising:

applying a particular label to packets comprising a TCP/HTTP connection from a forward proxy in front of an enterprise network, to a reverse proxy in front of a server farm network, said enterprise network having at least one client, including the steps of;

forming a communication channel between the forward proxy and the reverse proxy;

sending upon said communication channel a mapping of at least one MPLS label from the reverse proxy to the forward proxy; and

said forward proxy;

inspecting each request received from each client from said at least one client; and

assigning the particular label to all outgoing packets comprising the TCP/HTTP connection to an appropriate server in the server farm network;

said reverse proxy;

reading said particular label on all incoming packets; and

switching said incoming packets to the appropriate server within said server farm,

thereby identifying requested content which is otherwise performed after terminating the TCP/HTTP connection.

2. A method as recited in claim 1, where the step of inspecting is performed on an HTTP header.

3. A method as recited in claim 1, where the step of applying is employed in accordance with a URL of content being requested, and in accordance with said mapping.

4. A method as recited in claim 3, wherein said mapping is a mapping of URLs to MPLS labels.

5. A method as recited in claim 1, wherein the server farm network is MPLS enabled and the step switching includes employing an MPLS switch as the reverse proxy.

6. A method as recited in claim 1, wherein the server farm network is not MPLS enabled and the step of reading includes:

receiving an incoming packet having an incoming label;

identifying a corresponding outgoing port and outgoing IP address based on the incoming label in said incoming packet;

removing said incoming label and encapsulating said incoming packet with said outgoing IP address in forming an encapsulated packet; and

forwarding said encapsulated packet on said outgoing port.

7. A method as recited in claim 1, wherein the step of reading includes:

receiving an incoming packet having an incoming label;

identifying a corresponding outgoing port and outgoing Ethernet medium access control (MAC) address based on the incoming label in said incoming packet;

replacing said incoming label with said MAC address;

forwarding said incoming packet having said MAC address on said outgoing port.

8. A method as recited in claim 1, where the step of applying is employed in accordance with a load balancing criterion.

9. A method as recited in claim 8, wherein said mapping is a label listing.

10. A method as recited in claim 1, where the step of applying is employed in accordance with a service differentiation criterion.

11. A method as recited in claim 10, wherein said mapping is one or more prioritized labels.

12. A method as recited in claim 1, where the step of applying is employed in accordance with a client affinity criterion.

13. A method as recited in claim 12, wherein said mapping is a label listing, and said forward proxy assigning a common label to all requests from a particular client, such that each client is assigned a different label.

46. An article of manufacture comprising a computer usable medium having computer readable program code means embodied therein for causing application of at least one label, the computer readable program code means in said article of manufacture comprising computer readable program code means for causing a computer to effect the steps of claim 1.

14. An apparatus comprising:

means for applying a particular label to packets comprising a TCP/HTTP connection from a forward proxy in front of an enterprise network, to a reverse proxy in front of a server farm network, said enterprise network having at least one client, said means for applying including;

means for forming a communication channel between the forward proxy and the reverse proxy;

means for sending upon said communication channel a mapping of at least one MPLS label from the reverse proxy to the forward proxy; and

said forward proxy having;

means for inspecting each request received from each client from said at least one client; and

means for assigning the particular label to all outgoing packets comprising the TCP/HTTP connection to an appropriate server in the server farm network;

said reverse proxy having;

means for reading said particular label on all incoming packets; and

means for switching said incoming packets to the appropriate server within said server farm,

thereby identifying requested content which is otherwise identified after terminating the TCP/HTTP connection.

52. A computer program product comprising a computer usable medium having computer readable program code means embodied therein for causing application of a particular label, the computer readable program code means in said computer program product comprising computer readable program code means for causing a computer to effect the functions of claim 14.

15. A method comprising:

applying a particular label to packets comprising a TCP/HTTP connection from a forward proxy in front of an enterprise network, to a reverse proxy in front of a server farm network, said enterprise network having at least one client, including the steps of;

forming a communication channel between the forward proxy and the reverse proxy;

sending upon said communication channel a mapping of at least one MPLS label from the reverse proxy to the forward proxy; and

said forward proxy;

inspecting each request received from each client from said at least one client; and

assigning the particular label to all outgoing packets comprising the TCP/HTTP connection to an appropriate server in the server farm network.

47. An article of manufacture comprising a computer usable medium having computer readable program code means embodied therein for causing application of a particular label, the computer readable program code means in said article of manufacture comprising computer readable program code means for causing a computer to effect the steps of claim 15.

16. A method comprising:

forming a communication channel between a forward proxy and a reverse proxy, said forward proxy being in front of an enterprise network, and said reverse proxy being in front of a server farm network,

the reverse proxy reading a particular label on all incoming packets, and

switching said incoming packets to an appropriate server within the server farm network,

wherein the forward proxy;

applied the particular label to packets comprising a TCP/HTTP connection from the forward proxy to the reverse proxy, said enterprise network having at least one client, sent upon said communication channel a mapping of at least one MPLS label from the reverse proxy to the forward proxy;

inspected each request received from each client from said at least one client; and

assigned the particular label to all outgoing packets comprising the TCP/HTTP connection to the appropriate server in the server farm network, thereby identifying requested content which is otherwise identified after terminating the TCP/HTTP connection.

48. An article of manufacture comprising a computer usable medium having computer readable program code means embodied therein for causing switching of packets based on labels, the computer readable program code means in said article of manufacture comprising computer readable program code means for causing a computer to effect the steps of claim 16.

17. A method comprising:

applying a specific port to packets comprising a Web request on a TCP/HTTP connection from a forward proxy in front of an enterprise network, said enterprise network having at least one client, to a reverse proxy in front of a server farm network, including the steps of;

forming a communication channel between the forward proxy and the reverse proxy;

sending upon said communication channel a mapping of at least on TCP Port number from the reverse proxy to the forward proxy; and

said forward proxy;

inspecting each request received from each client from said at least one client; and

assigning said TCP port number to all outgoing packets comprising the TCP/HTTP connection to an appropriate server in the server farm network;

said reverse proxy;

reading said TCP port number on all incoming packets; and

replacing the TCP port number and IP address of the incoming packet with a port number of HTTP server and IP address of an appropriate server,

thereby identifying requested content which is otherwise identified after terminating the TCP/HTTP connection.

18. A method as recited in claim 17, where the step of inspecting is performed on an HTTP header.

19. A method as recited in claim 17, where the step of applying is employed in accordance with a URL of content being requested, and in accordance with said mapping.

20. A method as recited in claim 19, wherein said mapping is a mapping of URLs to TCP port numbers.

21. A method as recited in claim 17, where the step of applying is employed in accordance with a load balancing criterion.

22. A method as recited in claim 21, wherein said mapping is a listing of TCP port numbers

23. A method as recited in claim 17, where the step of applying is employed in accordance with a service differentiation criterion.

24. A method as recited in claim 23, wherein said mapping is one or more prioritized TCP port numbers.

25. A method as recited in claim 17, where the step of applying is employed in accordance with a client affinity criterion.

26. A method as recited in claim 25, wherein said mapping is a listing of TCP port numbers, and said forward proxy assigning a common TCP port number to all requests from a particular client, such that each client is assigned a different TCP port number for all connection requests from said each client.

49. An article of manufacture comprising a computer usable medium having computer readable program code means embodied therein for causing application of a specific port to packets, the computer readable program code means in said article of manufacture comprising computer readable program code means for causing a computer to effect the steps of claim 17.

27. A method comprising:

using MPLS labels for web switching, including the steps of;

obtaining a set of labels at a forward proxy for use with client Web requests;

applying a stack of said labels on packets comprising said client Web requests at said forward proxy; and

switching said packets at the reverse proxy based on said label stack.

28. A method as recited in claim 27, further comprising obtaining said set of labels through a communication channel between said forward proxy and said reverse proxy, or through an agent of said reverse proxy.

29. A method as recited in claim 28, wherein said agent is a specialized label distribution server.

30. A method as recited in claim 27, further comprising embedding said set of labels in a URL (Uniform Resource Locator) of said client Web requests, and the step of obtaining includes extracting said set of labels from said URL.

31. A method as recited in claim 27, further comprising applying said stack of labels in accordance with a URL of said client Web requests.

32. A method as recited in claim 27, further comprising applying said stack of labels in accordance with an identity of a client making said client Web request.

33. A method as recited in claim 27, further comprising applying said stack of labels in accordance with client session affinity criterion.

34. A method as recited in claim 27, further comprising applying said stack of labels in accordance with load distribution criterion.

50. An article of manufacture comprising a computer usable medium having computer readable program code means embodied therein for causing application of a stack of said labels on packets, the computer readable program code means in said article of manufacture comprising computer readable program code means for causing a computer to effect the steps of claim 27.

35. An apparatus serving as a forward proxy comprising:

an HTTP proxy module which receives client Web requests, and can make connections to Web servers on behalf of clients;

a request inspector module to inspect said requests;

a label applicator module which applies a label stack to packets belonging to said requests in forming labeled requests; and

a label map which contains a mapping of client request to label or TCP port number;

a label communicator module which receives said mapping from a reverse proxy and stores it in the label map.

a means for forwarding said labeled packets to a reverse proxy.

53. A computer program product comprising a computer usable medium having computer readable program code means embodied therein for causing a proxy to serve as a forward proxy, the computer readable program code means in said computer program product comprising computer readable program code means for causing a computer to effect the functions of claim 35.

36. An apparatus serving as a reverse proxy comprising:

an MPLS label-switched router (LSR),

a label switching table to determine an outgoing port and outgoing label for an incoming port and incoming label;

a module for receiving and inspecting labeled packets to identify the corresponding outgoing port and outgoing label based on the label switching table;

a packet switcher module for switching said incoming labeled packets to said outgoing port after replacing said incoming label with said outgoing label;

a label communicator for sending label mappings to the forward proxy;

a label programming interface to allow installation and modification of the label switching table.

54. A computer program product comprising a computer usable medium having computer readable program code means embodied therein for causing a proxy to serve as a reverse proxy, the computer readable program code means in said computer program product comprising computer readable program code means for causing a computer to effect the functions of claim 36.

37. An apparatus serving as a reverse proxy comprising:

an MPLS label-switched router (LSR);

a label switching table to determine an outgoing port and outgoing IP address for an incoming port and incoming label;

a module for receiving and inspecting labeled packets to identify the corresponding outgoing port and outgoing IP address based on the label switching table;

a packet switcher module for removing said incoming label and encapsulating said packet with said IP address, and for forwarding said encapsulated packet on said outgoing port.

a label communicator for sending label mappings to the forward proxy;

a label programming interface to allow installation and modification of the label switching table.

38. An apparatus serving as a reverse proxy comprising:

an MPLS label-switched router;

a label switching table to determine an outgoing port and outgoing MAC layer address for an incoming port and incoming label;

a module for receiving and inspecting labeled packets to identify the corresponding outgoing port and outgoing MAC layer address based on the label switching table;

a packet switcher module for removing said incoming label and applying said MAC layer address, and for forwarding said packet on said outgoing port;

a label communicator module for sending label mappings to the forward proxy;

a label programming interface to allow installation and modification of the label switching table.

39. A method comprising:

using TCP port numbers for web switching including the steps of;

obtaining a set of port numbers at the forward proxy for use with client Web requests;

using a port number from the said set of port numbers on packets comprising said client requests at said forward proxy; and

switching said packets at the reverse proxy based on said port number by replacing the IP address and said port number with a new IP address and port number.

40. A method as recited in claim 39, further comprising obtaining said set of port numbers through a communication channel between said forward proxy and said reverse proxy, or between said forward proxy and an agent of said reverse proxy.

41. A method as recited in claim 39, further comprising embedding said set of port numbers in a URL of said client Web requests, and extracting said set of labels from said URL.

42. A method as recited in claim 39, further comprising applying said port number in accordance with a URL of said client Web requests.

43. A method as recited in claim 39, further comprising applying said port number in accordance with an identity of the client making said client Web request.

44. A method as recited in claim 39, further comprising applying said port number in accordance with a criterion to maintain client session affinity.

45. A method as recited in claim 39, further comprising applying said port number in accordance with a load distribution criterion

51. An article of manufacture comprising a computer usable medium having computer readable program code means embodied therein for causing use of TCP port numbers for web switching, the computer readable program code means in said article of manufacture comprising computer readable program code means for causing a computer to effect the steps of claim 39.