Techniques for oversubscribing edge nodes for virtual private networks

• US 8,059,527 B2
• Filed: 11/16/2005
• Issued: 11/15/2011
• 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
• Primary Examiner(s): ROBERTS, BRIAN S
• Application Number:
  US11/281,269
• Publication Number:
  US 20060187937A1
• Time in Patent Office: 2,190 Days
• Field of Search: None
• US Class Current: 370/225
• 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, comprising:

evaluating activity associated with a particular attachment circuit during a first threshold interval, wherein if no network traffic is detected over a port associated with the particular attachment circuit during the first threshold interval, then a ping message is sent and a second threshold interval is evaluated for a response to the ping message;

determining whether a sign of death (SOD) is indicated on the particular attachment circuit, wherein an out-of-band event is received that is indicative of the particular attachment circuit being terminated;

initiating a new network action at an intermediate network node in response to determining that the SOD is indicated on the particular attachment circuit; and

receiving configuration data for configuring a plurality of additional attachment circuits at a network interface, and wherein the configuration data is received at a provisioning server that indicates participating provider edge nodes in a provider network and a respective level of service pertaining to per-hop behavior (PHB) parameters for a plurality of pseudowires that span between the participating provider edge nodes.

2. A method as recited in claim 1, said step of initiating the new network action further comprising removing the particular attachment circuit from association with a particular virtual private network so that network resources associated with switching the particular 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 1 said step of determining whether the SOD is indicated on the particular attachment circuit further comprising determining whether the network interface receives a message that indicates a request to tear down the particular attachment circuit.

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

6. A method as recited in claim 1 said step of determining whether the SOD is indicated on the particular attachment circuit further comprising receiving a message from a subscription server that a customer subscription for the particular attachment circuit has ended.

7. An apparatus, comprising:

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 perform operations, comprising;

evaluating activity associated with a particular attachment circuit during a first threshold interval, wherein if no network traffic is detected over a port associated with the particular attachment circuit during the first threshold interval, then a ping message is sent and a second threshold interval is evaluated for a response to the ping message;

determining whether a sign of death (SOD) is indicated on a particular attachment circuit, wherein an out-of-band event is received that is indicative of the particular attachment circuit being terminated;

initiating a new network action at an intermediate network node in response to determining that the SOD is indicated on the particular attachment circuit; and

receiving configuration data for configuring a plurality of additional attachment circuits at a network interface, and wherein the configuration data is received at a provisioning server that indicates participating provider edge nodes in a provider network and a respective level of service pertaining to per-hop behavior (PHB) parameters for a plurality of pseudowires that span between the participating provider edge nodes.

8. An apparatus as recited in claim 7, said step of initiating the new network action further comprising automatically removing the particular attachment circuit from association with a particular virtual private network so that network resources associated with switching the particular attachment circuit are released for switching a second attachment circuit with a second virtual private network.

9. An apparatus as recited in claim 7 said step of determining whether the SOD is indicated on the particular attachment circuit further comprising determining whether the network interface receives a message that indicates a request to tear down the particular attachment circuit.

10. An apparatus as recited in claim 7 said step of determining whether the SOD is indicated on the particular attachment circuit further comprising determining whether a threshold time is exceeded by a elapsed time since the network interface sent to a customer network node a message requesting a response message and no response message is received.

11. An apparatus as recited in claim 7 said step of determining whether the SOD is indicated on the particular attachment circuit further comprising receiving a message from a subscription server that a customer subscription for the particular attachment circuit has ended.