Dynamic construction of label switching protocol interfaces

• US 7,978,602 B2
• Filed: 11/14/2005
• Issued: 07/12/2011
• Est. Priority Date: 11/14/2005
• Status: Active Grant

• Current Assignee: Juniper Networks Incorporated
• Original Assignee: Juniper Networks Incorporated
• Inventors: Rijsman, Bruno
• Primary Examiner(s): Wu; Jianye
• Application Number:
  US11/273,010
• Publication Number:
  US 20080069110A1
• Time in Patent Office: 2,066 Days
• Field of Search: 370/395.5, 370/352, 370/465, 709/238
• US Class Current: 370/230
• CPC Class Codes: H04L 12/4633 Interconnection of networks using encapsulation techniques, e.g. tunneling
• CPC Class Codes: H04L 45/04 Interdomain routing, e.g. hierarchical routing
• CPC Class Codes: H04L 45/50 using label swapping, e.g. multi-protocol label switch [MPLS]

Abstract

Techniques are described for dynamically constructing a label switching protocol interface in a network device. For example, the techniques allow dynamic construction of a Multi-Protocol Label Switching (MPLS) interface. According to some embodiments, upon receiving a network communication from a subscriber, a network device determines whether the subscriber requires support for the label switching protocol. If the subscriber requires such support, the network device creates an interface stack for the subscriber that includes an interface for the label switching protocol. In this way, the network device may route packets from the subscriber across a network of computing devices that use the label switching protocol, and forward packets from such a network to the subscriber. The subscriber and the network device need not communicate according to the label switching protocol and, in example embodiments, instead communicate according to a layer 2 communication protocol.

Claims

1. A method comprising:

receiving, with a network access device, a network access request from a subscriber device associated with a subscriber,

determining, with the network access device, when the network access request is received, whether the subscriber device requires a label switching protocol interface for encapsulating and decapsulating traffic associated with the subscriber device according to the label switching protocol for communication with a label switching network;

in response to receiving the network access request and upon determining that the subscriber device requires the label switching protocol interface, dynamically constructing a software interface stack on the network access device that includes a plurality of interfaces, each of the interfaces associated with a respective one of a plurality of protocols, wherein the plurality of interfaces includes the label switching protocol interface; and

subsequent to dynamically constructing the software interface stack on the network access device, processing network communications from the subscriber device with the software interface stack of the network access device and routing the network communications from the network access device to the label switching network.

2. The method of claim 1, wherein the label switching protocol is a Multi-Protocol Label Switching (MPLS) protocol.

3. The method of claim 1, wherein the network access request comprises a Dynamic Host Configuration Protocol (DHCP) discover message or a Point-to-Point Protocol (PPP) configure request message.

4. The method of claim 1, further comprising authenticating the subscriber, wherein constructing the software interface stack comprises constructing the software interface stack based on the determination and the authentication.

5. The method of claim 4, wherein authenticating the subscriber comprises:

receiving an authentication credential from the subscriber device as part of the network access request; and

providing the authentication credential to an authentication service.

6. The method of claim 5, wherein providing the authentication credential to an authentication service comprises providing the authentication credential to a Remote Access Dial-In User Service (RADIUS) server.

7. The method of claim 1, wherein determining whether the subscriber device requires the label switching protocol interface comprises determining whether a subscriber profile associated with the subscriber specifies that the subscriber device requires the label switching protocol interface, wherein a network service provider that is different that the subscriber configures the subscriber profile for the subscriber.

8. The method of claim 7, further comprising storing the subscriber profile locally within the network access device that receives the network access request from the subscriber device.

9. The method of claim 7, further comprising retrieving the subscriber profile from a data store.

10. The method of claim 9, wherein retrieving the subscriber profile from a data store comprises retrieving the subscriber profile from a Remote Access Dial-In User Service (RADIUS) server.

11. The method of claim 1, wherein receiving the network access request from a subscriber device comprises receiving the network access request with a network card of the network access device, and wherein constructing a software interface stack comprises constructing the software interface stack within the network card of the network access device.

12. The method of claim 1, further comprising:

receiving a non-label switching protocol packet from the subscriber device; and

using the label switching protocol interface to create a label switching protocol packet that includes the non-label switching protocol packet.

13. The method of claim 1, further comprising:

receiving a label switching protocol packet destined for the subscriber device from a network;

using the label switching protocol interface to create a non-label switching protocol packet by removing a label switching protocol header of the label switching protocol packet; and

forwarding the non-label switching protocol packet to the subscriber device.

32. The method of claim 1, wherein the plurality of interfaces comprises at least one of an Ethernet interface, a point-to-point protocol interface, or a virtual local area network interface, wherein constructing the software interface stack comprises constructing the software interface stack with the label switching protocol interface over the at least one of the Ethernet interface, the point-to-point protocol interface, or the virtual local area network interface.

33. The method of claim 12, wherein the non-label switching protocol packet is a layer 2 packet.

34. The method of claim 1, further comprising:

receiving a label switching protocol packet from the subscriber device; and

interpreting a label of the label switching protocol packet with the label switching protocol interface to determine how to forward the label switching protocol packet across the label switching network.

35. The method of claim 1, wherein the network access device is a broadband remote access server (BRAS).

14. A non-transitory computer-readable medium comprising instructions for execution by a processor of a network access device, wherein the instructions cause the processor to:

receive a network access request from a subscriber device associated with a subscriber that does not have administrative access to the network access device;

determine, when the network access request is received, whether the subscriber device requires a label switching protocol interface for encapsulating and decapsulating traffic associated with the subscriber device according to the label switching protocol for communication with the label switching network; and

in response to receiving the network access request and upon determining that the subscriber device requires the label switching protocol interface, dynamically construct a software interface stack on the network access device that includes a plurality of interfaces based on the determination, each of the interfaces associated with a respective one of a plurality of protocols, wherein the plurality of interfaces includes the label switching protocol interface; and

subsequent to dynamically constructing the software interface stack on the network access device, process network communications from the subscriber device with the software interface stack of the network access device and route the network communications from the network access device to the label switching network.

15. The non-transitory computer-readable medium of claim 14, wherein the instructions that cause a processor to determine whether a label switching protocol interface is required comprise instructions that cause a processor to determine whether a subscriber profile associated with the subscriber specifies that the subscriber device requires the label switching protocol interface.

16. The non-transitory computer-readable medium of claim 14, further comprising instructions that cause a processor to retrieve the subscriber profile from a data store.

17. The non-transitory computer-readable medium of claim 16, wherein the instructions that cause a processor to retrieve the subscriber profile comprise instructions that cause a processor to retrieve the subscriber profile from a Remote Access Dial-In Service (RADIUS) server.

18. The non-transitory computer-readable medium of claim 14, further comprising instructions that cause a processor to:

receive a non-label switching protocol packet from the subscriber device; and

use the label switching protocol interface to create a label switching protocol packet that includes the non-label switching protocol packet.

19. The non-transitory computer-readable medium of claim 14, further comprising instructions that cause a processor to:

receive a label switching protocol packet destined for the subscriber device from a network;

use the label switching protocol interface to create a non-label switching protocol packet by removing a label switching protocol header of the label switching protocol packet; and

forward the non-label switching protocol packet to the subscriber device.

36. The non-transitory computer-readable medium of claim 14, wherein the network access device is a broadband remote access server (BRAS).

20. A network access device comprising:

a network interface card that receives a network access request from the subscriber; and

a control unit that;

routes network packets from the subscriber to the label switching network;

determines, when the network access request is received, whether the subscriber requires a label switching protocol interface for encapsulating and decapsulating traffic associated with the subscriber according to the label switching protocol for communication with the label switching network; and

in response to receipt of the network access request and upon a determination that the subscriber requires the label switching protocol interface, controls dynamic construction of a software interface stack that includes a plurality of interfaces for the subscriber on the network interface card based on the determination, each of the interfaces associated with a respective one of a plurality of protocols, wherein the plurality of interfaces includes the label switching protocol interface,

wherein the network interface card processes network communications from the subscriber device with the software interface stack and routes the network communications to the label switching network.

21. The network access device of claim 20, wherein the label switching protocol is a Multi-Protocol Label Switching (MPLS) protocol.

22. The network access device of claim 20, wherein the network access request comprises a Dynamic Host Configuration Protocol (DHCP) discover message or a Point-to-Point Protocol (PPP) configure request message.

23. The network access device of claim 20, wherein the control unit authenticates the subscriber, and controls construction of the software interface stack based on the authentication.

24. The network access device of claim 20, wherein the control unit determines whether a subscriber profile associated with the subscriber specifies that the subscriber device requires the label switching protocol interface.

25. The network access device of claim 24, wherein the control unit retrieves the subscriber profile from a Remote Access Dial-In Service (RADIUS) server.

26. The network access device of claim 24, further comprising a subscriber profile cache that caches the subscriber profile locally.

27. The network access device of claim 20, wherein the network interface card comprises:

a forwarding component that receives the network access request from the subscriber device;

an interface controller that determines whether the interface stack exists on the network card; and

a dynamic configuration manager that constructs the interface stack on the network card as directed by the control unit.

28. The network access device of claim 20, wherein the network interface card receives a non-label switching protocol packet from the subscriber device, and uses the label switching protocol interface to create a label switching protocol packet that includes the non-label switching protocol packet.

29. The network access device of claim 20, wherein the network interface card receives a label switching protocol packet destined for the subscriber device from the network, uses the label switching protocol interface to create a non-label switching protocol packet by removing a label switching protocol header from the label switching protocol packet, and forwards the non-label switching protocol packet to the subscriber device.

30. The network access device of claim 20, wherein the network access device is a router.

37. The network access device of claim 20, wherein the network access device is a broadband remote access server (BRAS).

31. A method comprising:

receiving, with a network card of a network access device, a network access request from a subscriber device;

sending an authentication request from the network access device to a remote authentication service in response to the network access request;

receiving a subscriber profile from the authentication service at the network access device in response to the request, the subscriber profile indicating that the subscriber device requires a label switching protocol interface for encapsulating and decapsulating traffic associated with the subscriber according to the label switching protocol for communication with a label switching network; and

constructing a software interface stack that includes a plurality of interfaces on the network access device for the subscriber on the network card according to the subscriber profile, each of the interfaces associated with a respective one of a plurality of protocols, wherein the plurality of interfaces includes the label switching protocol interface; and

processing network communications from the subscriber device with the software interface stack of the network access device and routing the network communications from the network access device to the label switching network.