Techniques for oversubscribing edge nodes for virtual private networks

• US 20060187937A1
• Filed: 11/16/2005
• Published: 08/24/2006
• Est. Priority Date: 02/19/2005
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Townsley, William Mark, Booth, Earl Hardin III
• Granted Patent: US 8,059,527 B2
• Time in Patent Office: Days
• US Class Current: 370/395.530
• CPC Class Codes: H04J 3/16 in which the time allocation to individual channels within a transmission cycle is variable, e.g. to accommodate varying complexity of signals, to vary number of channels transmitted H04J3/17, H04J3/24 take precedence
• CPC Class Codes: H04J 3/22 in which the sources have different rates or codes simultaneous speech and digital data or video transmission H04M11/06; see provisional also H04J3/16
• CPC Class Codes: H04L 12/28 characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks] wireless communication networks H04W ; arrangements for dividing the transmission path H04W40/00
• CPC Class Codes: H04L 12/4633 Interconnection of networks using encapsulation techniques, e.g. tunneling
• CPC Class Codes: H04L 12/4641 Virtual LANs, VLANs, e.g. virtual private networks [VPN] LAN interconnection over a bridge based backbone H04L12/462; encapsulation techniques H04L12/4633; routing of packets H04L45/00; packet switches H04L49/00; virtual private networks for security H04L63/0272
• CPC Class Codes: H04L 12/56 Packet switching systems
• CPC Class Codes: H04L 41/0631 using root cause analysis; using analysis of correlation between notifications, alarms or events based on decision criteria, e.g. hierarchy, tree or time analysis
• CPC Class Codes: H04L 41/0886 Fully automatic configuration
• CPC Class Codes: H04L 43/0876 Network utilisation, e.g. volume of load or congestion level

Abstract

Techniques for operating a network interface include automatically determining whether communications are terminated over a particular attachment circuit on a network interface on an intermediate network node at an edge of a provider network, whereby a sign of death (SOD) on the particular attachment circuit is indicated. The attachment circuit is switched with a particular virtual private network that is a link layer virtual private network (VPN) encapsulated in a higher layer protocol. The provider network is a packet-switched network. The network interface is for a direct communication link to a customer network node outside the provider network. If it is determined that there is an indication of the SOD, then a new network action is initiated in response to the SOD on the particular attachment circuit. These techniques allow for automatic logging of usage, billing, and fault detection, as well as for over-subscription of network resources for multiple VPNs.

Claims

1. A method for operating a network interface on an intermediate network node at an edge of a provider network to support a virtual private network, comprising the steps of:

automatically determining whether communications are terminated over a particular attachment circuit on a network interface on an intermediate network node at an edge of a provider network, which attachment circuit is switched with a particular virtual private network, whereby a sign of death (SOD) on the particular attachment circuit is indicated; and

if it is determined that there is an indication of the SOD, then initiating a new network action in response to the SOD on the particular attachment circuit

wherein

the provider network is a packet-switched network;

the particular virtual private network is a link layer virtual private network encapsulated in a protocol above the link layer; and

the network interface is for a direct communication link to a customer network node outside the provider network.

2. A method as recited in claim 1, said step of initiating the new network action further comprising automatically removing the attachment circuit from association with the particular virtual private network so that network resources associated with switching the attachment circuit at the network interface with the particular virtual private network are released for switching a second attachment circuit with a second virtual private network.

3. A method as recited in claim 2 said step of initiating the new network action further comprising automatically configuring the network interface to switch the second attachment circuit with the second virtual private network.

4. A method as recited in claim 3 further comprising receiving configuration data for automatically configuring a plurality of attachment circuits at the network interface, wherein the total resources consumed by the plurality of attachment circuits exceed a capacity of the network interface, whereby the network interface is over-subscribed.

5. A method as recited in claim 1 said step of determining whether there is an indication of the SOD further comprising determining whether a threshold time is exceeded by an elapsed time since the network interface most recently received a message that indicates a request to keep the attachment circuit alive.

6. A method as recited in claim 1 said step of determining whether there is an indication of the SOD further comprising determining whether a threshold time is exceeded by an elapsed time since the network interface most recently received any message over the attachment circuit.

7. A method as recited in claim 1 said step of determining whether there is an indication of the SOD further comprising determining whether the network interface receives a message that indicates a request to tear down the attachment circuit.

8. A method as recited in claim 1 said step of determining whether there is an indication of the SOD further comprising determining whether a threshold time is exceeded by an elapsed time since the network interface sent to the customer network node a message requesting a response message and no response message is received.

9. A method as recited in claim 1 said step of determining whether there is an indication of the SOD further comprising receiving a message from a subscription server that a customer subscription for the attachment circuit has ended.

10. An apparatus for processing a signal on a network interface on an intermediate network node at an edge of a provider network to support a virtual private network, comprising:

means for automatically determining whether communications are terminated over a particular attachment circuit on a network interface on an intermediate network node at an edge of a provider network, which attachment circuit is switched with a particular virtual private network, whereby a sign of death (SOD) on the particular attachment circuit is indicated; and

means for initiating a new network action in response to the SOD on the particular attachment circuit if it is determined that there is an indication of the SOD,

wherein

the provider network is a packet-switched network;

the particular virtual private network is a link layer virtual private network encapsulated in a protocol above the link layer; and

the particular interface is for a direct communication link to a customer network node outside the provider network.

11. An apparatus for configuring a network interface on an intermediate network node at an edge of a provider network to support a virtual private network, comprising:

a provider network interface that is coupled to a provider network for communicating therewith a data packet;

a customer network interface that is coupled to customer premises equipment outside the provider network for communicating therewith a data packet;

one or more processors;

a computer-readable medium; and

one or more sequences of instructions stored in the computer-readable medium,

which, when executed by the one or more processors, causes the one or more processors to carry out the step of;

automatically determining whether communications are terminated over a particular attachment circuit on a network interface on an intermediate network node at an edge of a provider network, which attachment circuit is switched with a particular virtual private network, whereby a sign of death (SOD) on the particular attachment circuit is indicated; and

if it is determined that there is an indication of the SOD, then initiating a new network action in response to the SOD on the particular attachment circuit

wherein

the provider network is a packet-switched network;

the particular virtual private network is a link layer virtual private network encapsulated in a protocol above the link layer; and

the particular interface is for a direct communication link to a customer network node outside the provider network.

12. An apparatus as recited in claim 11, said step of initiating the new network action further comprising automatically removing the attachment circuit from association with the particular virtual private network so that network resources associated with switching the attachment circuit at the network interface with the particular virtual private network are released for switching a second attachment circuit with a second virtual private network.

13. An apparatus as recited in claim 12 said step of initiating the new network action further comprising automatically configuring the network interface to switch the second attachment circuit with the second virtual private network.

14. An apparatus as recited in claim 13 further comprising receiving configuration data for automatically configuring a plurality of attachment circuits at the network interface, wherein the total resources consumed by the plurality of attachment circuits exceed a capacity of the network interface, whereby the network interface is over-subscribed.

15. An apparatus as recited in claim 11 said step of determining whether there is an indication of the SOD further comprising determining whether a threshold time is exceeded by an elapsed time since the network interface most recently received a message that indicates a request to keep the attachment circuit alive.

16. An apparatus as recited in claim 11 said step of determining whether there is an indication of the SOD further comprising determining whether a threshold time is exceeded by an elapsed time since the network interface most recently received any message over the attachment circuit.

17. An apparatus as recited in claim 11 said step of determining whether there is an indication of the SOD further comprising determining whether the network interface receives a message that indicates a request to tear down the attachment circuit.

18. An apparatus as recited in claim 11 said step of determining whether there is an indication of the SOD further comprising determining whether a threshold time is exceeded by an elapsed time since the network interface sent to the customer network node a message requesting a response message and no response message is received.

19. An apparatus as recited in claim 11 said step of determining whether there is an indication of the SOD further comprising receiving a message from a subscription server that a customer subscription for the attachment circuit has ended.