Method and apparatus for redirecting packets using encapsulation

• US 6,247,054 B1
• Filed: 03/24/1997
• Issued: 06/12/2001
• Est. Priority Date: 03/24/1997
• Status: Expired due to Term

• Current Assignee: RPX Clearinghouse LLC (RPX Corporation)
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Malkin, Gary
• Primary Examiner(s): Burgess, Glenton B.
• Assistant Examiner(s): FIELDS, KENNETH WAYNE
• Application Number:
  US08/822,848
• Time in Patent Office: 1,541 Days
• Field of Search: 395/200.31, 395/200.32, 395/200.33, 395/200.36, 395/200.49, 395/200.55, 395/200.56, 709/201, 709/202, 709/203, 709/206, 709/219, 709/225, 709/226
• US Class Current: 709/225
• CPC Class Codes: H04L 69/22 Parsing or analysis of headers

Abstract

A method and apparatus for redirecting packets using encapsulation techniques. In one embodiment, an Internet subscriber transmits an Internet service request to a Network Access Server (NAS). The service request is transmitted in a first packet. The NAS analyzes the first packet to determine whether the service request exceeds the subscriber'"'"'s internet subscription. If the request exceeds the subscriber'"'"'s subscription, the NAS encapsulates the first packet into a second packet and redirects the second to a redirection server. The packet is encapsulated to preserve the address of the original destination of the service request. Upon receipt, the redirection server generates a reply to the internet service request which specifies why the service request was denied. The redirection server also substitutes the address of the original destination as the source of the reply message to allow the reply message to be received as reply from the original destination.

Claims

1. A method for selectively redirecting packets of information, said method comprising:

a) receiving a first packet of information from a first source, said first packet of information having a first destination specified in a header of said first packet of information;

b) examining said first packet to determine whether a service request of said first packet exceeds a pre-determined service level available to said first source; and

c) processing said first packet of information to redirect said first packet of information to a second destination in place of said first destination if said first packet exceeds said pre-determined service level available to said first source, wherein said first packet of information is processed to be redirected to said second destination and include said first destination as specified in said header of said first packet of information, said step of processing enables said second destination to generate a reply packet to said first source, and said reply packet identifies said first destination as a source of said reply packet.

2. The method of claim 1, wherein the method is performed by a Network Access Server (NAS).

3. The method of claim 1, wherein said processing said first packet of information includes encapsulating said first packet of information into a second packet of information.

4. The method of claim 3, wherein said first packet includes a service request to an Internet Service Provider (ISP), and said reply packet generated by said second destination includes a message indicating said service request of said first packet exceeds said pre-determined service level available to said first source.

5. The method of claim 1 wherein the method is performed by a switching system product.

6. The method of claim 1 wherein the method is performed by a transmissions system product.

7. A computer-readable medium having stored thereon a plurality of instructions, including a first set of instructions for selectively redirecting packets of information, said first set of instructions, when executed by a processor, cause said processor to perform:

a) receiving a first packet of information from a first source, said first packet of information having a first destination specified in a header of said first packet of information;

b) examining said first packet to determine whether a service request of said first packet exceeds a pre-determined service level available to said first source; and

c) processing said first packet of information to redirect said first packet of information to a second destination in place of said first destination if said first packet exceeds said pre-determined service level available to said first source, wherein said first packet of information is processed to be redirected to said second destination and include said first destination as specified in said header of said first packet of information, said step of processing enables said second destination to generate a reply packet to said first source, and said reply packet identifies said first destination as a source of said reply packet.

8. The computer-readable medium of claim 7, wherein the first set of instructions are performed by a Network Access Server (NAS).

9. The computer-readable medium of claim 7, wherein said processing said first packet of information includes encapsulating said first packet of information into a second packet of information.

10. The computer-readable medium of claim 9, wherein said first packet includes a service request to an Internet Service Provider (ISP), and said reply packet generated by said second destination includes a message indicating said service request of said first packet exceeds said pre-determined service level available to said first source.

11. The computer-readable medium of claim 7 implemented on a switching system product.

12. The computer-readable medium of claim 7 implemented on a transmissions system product.

13. A Network Access System (NAS) comprising:

a) a first device operable to receive a first packet of information from a first source, said first packet of information having a first destination specified in a header of said first packet of information;

b) said first device operable to examine said first packet to determine whether a service request of said first packet exceeds a pre-determined service level available to said first source; and

c) said first device further operable to process said first packet of information to redirect said first packet of information to a second destination in place of said first destination if said first packet exceeds said pre-determined service level available to said first source, said first packet of information is processed to be redirected to said second destination and include said first destination as specified in said header of said first packet of information, said step of processing enables said second destination to generate a reply packet to said first source, and said reply packet identifies said first destination as a source of said reply packet.

14. The NAS of claim 13, wherein said first device is further operable to encapsulate said first packet of information into a second packet of information and redirect said second packet of information to said second device.

15. The NAS of claim 14, wherein said first packet includes a service request to an Internet Service Provider (ISP), and said reply packet generated by said second destination includes a message indicating said service request of said first packet exceeds said pre-determined service level available to said first source.

16. The NAS of claim 13 wherein the NAS comprises a switching system product.

17. The NAS of claim 13 wherein the NAS comprises a transmissions system product.

18. A computer-readable medium having stored thereon a plurality of instructions, including a first set of instructions for redirecting packets of information, said first set of instructions, when executed by a processor, cause said processor to perform:

a) receiving, at a first server, a packet from a client, the packet including a header that identifies a second server as the destination of the packet;

b) examining the packet to determine whether a service request associated with the packet exceeds a pre-determined service level available to the client;

c) preserving the destination of the packet by encapsulating the packet within a new packet; and

d) if said service request associated with the packet exceeds said predetermined service level available to the client, redirecting the new packet to a third server in place of the second server, said encapsulating the packet within the new packet enables the third server to generate a reply packet to the client, wherein the reply packet identifies the second server as the source of the reply packet.

19. The computer-readable medium of claim 18, wherein the first set of instructions are performed by a Network Access Server (NAS).

20. The computer-readable medium of claim 18, wherein the packet includes a service request to an Internet Service Provider (ISP), and the reply packet generated by the third server includes a message indicating the service request of the packet exceeds the pre-determined service level available to the client.

21. The computer-readable medium of claim 18 implemented on a switching system product.

22. The computer-readable medium of claim 18 implemented on a transmissions system product.

23. A Network Access System (NAS) comprising:

a) a first server operable to receive a packet of information from a client, the packet of information including a header that identifies a second server as the destination of the packet;

b) said first server operable to examine the packet to determine whether a service request associated with the packet exceeds a pre-determined service level available to the client; and

c) said first server further operable to preserve the destination of the packet by encapsulating the packet within a new packet; and

d) if said service request associated with the packet exceeds said predetermined service level available to the client, said first server further operable to redirect the new packet to a third server in place of the second server, the encapsulating the packet within the new packet enables the third server to generate a reply packet to the client, wherein the reply identifies the second server as the source of the reply packet.

24. The NAS of claim 23, wherein the packet includes a service request to an Internet Service Provider (ISP), and the reply packet generated by the third server includes a message indicating the service request of the packet exceeds said pre-determined service level available to the client.

25. The NAS of claim 23 implemented on a switching system product.

26. The NAS of claim 23 implemented on a transmissions system product.

27. An apparatus, comprising:

a) means for receiving, at a first server, a packet from a client, the packet including a header that identifies a second server as the destination of the packet;

b) means for examining the packet to determine whether a service request associated with the packet exceeds a pre-determined service level available to the client;

c) means for preserving the destination of the packet by encapsulating the packet within a new packet; and

d) means for determining that if said service request associated with the packet exceeds said predetermined service level available to the client, redirecting the new packet to a third server in place of the second server, said encapsulating the packet within the new packet enables the third server to generate a reply packet to the client, wherein the reply packet identifies the second server as the source of the reply packet.

28. The apparatus of claim 27, wherein the apparatus comprises a Network Access Server (NAS).

29. The apparatus of claim 27, wherein the packet includes a service request to an Internet Service Provider (ISP), and the reply packet generated by the third server includes a message indicating the service request of the packet exceeds the pre-determined service level available to the client.

30. The apparatus of claim 27 implemented on a switching system product.

31. The apparatus of claim 27 implemented on a transmissions system product.

32. A data signal embodied in a propagation medium, the data signal including a plurality of instructions, which when executed by a processor, cause the processor to:

a) receive, at a first server, a packet from a client, the packet including a header that identifies a second server as the destination of the packet;

c) examine the packet to determine whether a service request associated with the packet exceeds a pre-determined service level available to the client;

c) preserve the destination of the packet by encapsulating the packet within a new packet; and

d) if said service request associated with the packet exceeds said predetermined service level available to the client, redirect the new packet to a third server in place of the second server, said encapsulating the packet within the new packet enables the third server to generate a reply packet to the client, wherein the reply packet identifies the second server as the source of the reply packet.

33. The data signal of claim 32, wherein the plurality of instructions are executed by a Network Access Server (NAS).

34. The data signal of claim 32, wherein the packet includes a service request to an Internet Service Provider (ISP), and the reply packet generated by the third server includes a message indicating the service request of the packet exceeds the pre-determined service level available to the client.

35. The data signal of claim 32 implemented on a switching system product.

36. The data signal of claim 32 implemented on a transmissions system product.

37. A first network device that selectively redirects a packet that is transmitted from a client, where the packet identifies a second network device in a destination field of a header that is associated with the packet, in order to facilitate providing an indication of denial of access to a service associated with the packet, comprising:

a) at least one port through which the packet of information is received;

b) processing circuitry that assists examination of the packet to determine whether the service associated with the packet is available to the client; and

c) redirection circuitry that causes generation of a new packet that encapsulates the packet, and transmission of the new packet to a third network device in place of the second network device if the service associated with the packet is determined to be unavailable to the client, whereby said third network device is facilitated in providing, for transmission to the client, a reply packet that identifies the second network device in a source field of a header that is associated with the reply packet.

38. The apparatus of claim 37, wherein the first network device comprises a Network Access Server (NAS).

39. The first network device of claim 37, wherein said first packet includes a service request to an Internet Service Provider (ISP), and said reply packet generated by said third network device includes a message indicating said service request of said first packet exceeds a service level available to the client.

40. The first device of claim 37 implemented on a switching system product.

41. The first device of claim 37 implemented on a transmissions system product.

42. A method for selectively redirecting a packet that is transmitted from a client, where the packet identifies a first network device in a destination field of a header that is associated with the packet, in order to facilitate providing an indication of denial of access to a service associated with the packet, comprising the steps of:

receiving the packet at a second network device;

examining the packet to determine whether the service associated with the packet is available to the client; and

if the service associated with the packet is determined to be unavailable to the client, encapsulating the packet in a new packet and transmitting the new packet to a third network device in place of the first network device, whereby said third network device is facilitated in providing, for transmission to the client, a reply packet that identifies the second network device in a source field of a header that is associated with the reply packet.

43. The method of claim 42, wherein the method is performed by a Network Access Server (NAS).

44. The method of claim 42, wherein the packet includes a service request to an Internet Service Provider (ISP), and the reply packet generated by the third network device includes a message indicating the service request of the packet exceeds a service level available to the client.

45. The method of claim 42 wherein the method is performed by a switching system product.

46. The method of claim 42, wherein the method is performed by a transmissions system product.