Enhancing a mobile backup channel to address a node failure in a wireline network

Patent metadata

Field	Value
Publication number	US-9173117-B2
Application number	US-201313886081-A
Country	US
Kind code	B2
Filing date	May 2, 2013
Priority date	May 2, 2013
Publication date	Oct 27, 2015
Grant date	Oct 27, 2015

Abstract

A method performed by a slave network edge node (e.g., a Broadband Network Gateway BNG2) for enhancing a Long Term Evolution (LTE) backup channel in the event of a failure of a master network edge node (e.g., BNG1) in a wireline network. When BNG2 detects the failure of BNG1, BNG2 sends a failure update message to a Packet Data Network Gateway (PDN GW) of an LTE network. The PDN GW provides a backup channel for the CPE to reach the wide area network over a mobile tunnel. Before the failure the mobile tunnel has an end point at BNG1, and the failure update message notifies the PDN GW that the end point of the mobile tunnel has changed from BNG1 to BNG2. After BNG2 receives a failure acknowledgement message from the PDN GW, BNG2 routes the traffic from the PDN GW over the mobile tunnel to the wide area network.

First claim

What is claimed is:

1. A method implemented by a slave network edge node at an edge of a service provider network, the slave network edge node to provide accessibility to a wide area network for a customer premise equipment (CPE) upon a failure of a master network edge node, wherein the master network edge node is coupled to the CPE over a wireline link and provides accessibility to the wide area network for the CPE before the failure, the method comprising:
detecting that the master network edge node has failed;
sending a failure update message (BFU) by the slave network edge node to a Packet Data Network Gateway (PDN GW) of a Long-Term Evolution (LTE) network, wherein the PDN GW provides a backup channel for the CPE to reach the wide area network over a mobile tunnel, and wherein before the failure the mobile tunnel has an end point at the master network edge node, and wherein the failure update message notifies the PDN GW that the end point of the mobile tunnel has changed from the master network edge node to the slave network edge node;
receiving a failure acknowledgement message (BFA) by the slave network edge node from the PDN GW in response to the failure update message; and
routing traffic received by the slave network edge node from the PDN GW over the mobile tunnel to the wide area network.

2. The method of claim 1 , wherein detecting that the master network edge node has failed further comprises: detecting an absence of a keep-alive message from the master network edge node.

3. The method of claim 2 , further comprising: periodically exchanging a state of a second virtual gateway controller in the slave network edge node with a state of a first virtual gateway controller in the master network edge node until the failure of the master network edge node is detected, wherein the first virtual gateway controller and the second virtual gateway controller are adapted to perform control functions for the CPE.

4. The method of claim 1 , wherein detecting that the master network edge node has failed further comprises: exchanging keep-alive messages with the master network edge node and a virtual gateway controller, wherein the virtual gateway controller is coupled to both the master network edge node and the slave network edge node to perform control functions for the CPE.

5. The method of claim 3 , further comprising: notifying the virtual gateway controller that the end point of the mobile tunnel has changed from the master network edge node to the slave network edge node upon detecting the failure of the master network edge node.

6. The method of claim 1 , further comprising:
detecting traffic overload at the slave network edge node;
sending a first traffic offload request (TOR) by the slave network edge node to a peer network edge node, wherein the first traffic offload request includes a range of prefixes to be offloaded to the peer network edge node, such that network traffic identifying an address within the range is to be routed by the PDN GW to the peer network edge node instead of the slave network edge node; and
receiving a first traffic offload acknowledgement (TOA) from the peer network edge node.

7. The method of claim 6 , wherein sending the first traffic offload request further comprises:
sending a second traffic offload request by the slave network edge node to the PDN GW, wherein the second traffic offload request includes the range of prefixes to be offloaded to the peer network edge node and an address of the peer network edge node; and
receiving a second traffic offload acknowledgement from the PDN GW by the slave network edge node.

8. The method of claim 6 , wherein sending the first traffic offload request further comprises: determining the range of prefixes based on a current workload of the peer network edge node.

9. A network element serving as a slave network edge node at an edge of a service provider network, the network element to provide accessibility to a wide area network for a customer premise equipment (CPE) upon a failure of a master network edge node, wherein the master network edge node is coupled to the CPE over a wireline link and provides accessibility to the wide area network for the CPE before the failure, the network element comprising:
an uplink module to communicate with the wide area network;
a master/slave interface module to communicate with the master network edge node;
a Packet Data Network Gateway (PDN GW) interface module to communicate with a PDN GW of a Long-Term Evolution (LTE) network, wherein the PDN GW provides a backup channel for the CPE to reach the wide area network over a mobile tunnel, and wherein before the failure the mobile tunnel has an end point at the master network edge node; and
a network processor communicatively coupled to the uplink module, the master/slave interface module, and the PDN GW interface module, the network processor adapted to:
detect that the master network edge node has failed;
send a failure update message (BFU) to the PDN GW, wherein the failure update message notifies the PDN GW that the end point of the mobile tunnel has changed from the master network edge node to the slave network edge node;
receive a failure acknowledgement message (BFA) from the PDN GW in response to the failure update message; and
route traffic received from the PDN GW over the mobile tunnel to the wide area network.

10. The network element of claim 9 , wherein the network processor is further adapted to detect an absence of a keep-alive message from the master network edge node.

11. The network element of claim 10 , wherein the network processor is further adapted to periodically exchange a state of a second virtual gateway controller in the slave network edge node with a state of a first virtual gateway controller in the master network edge node until the failure of the master network edge node is detected, wherein the first virtual gateway controller and the second virtual gateway controller are adapted to perform control functions for the CPE.

12. The network element of claim 9 , wherein the network processor is further adapted to exchange keep-alive messages with the master network edge node and a virtual gateway controller, wherein the virtual gateway controller is coupled to both the master network edge node and the slave network edge node to perform control functions for the CPE.

13. The network element of claim 12 , wherein the network processor is further adapted to notify the virtual gateway controller that the end point of the mobile tunnel has changed from the master network edge node to the slave network edge node upon detecting the failure of the master network edge node.

14. The network element of claim 9 , wherein the network processor is further adapted to:
detect traffic overload at the slave network edge node;
send a first traffic offload request (TOR) by the slave network edge node to a peer network edge node, wherein the first traffic offload request includes a range of prefixes to be offloaded to the peer network edge node, such that network traffic identifying an address within the range is to be routed by the PDN GW to the peer network edge node instead of the slave network edge node; and
receive a first traffic offload acknowledgement (TOA) from the peer network edge node.

15. The network element of claim 14 , wherein the network processor is further adapted to:
send a second traffic offload request by the slave network edge node to the PDN GW, wherein the second traffic offload request includes the range of prefixes to be offloaded to the peer network edge node and an address of the peer network edge node; an

Assignees

• Ericsson Telefon Ab L M

Inventors

• Haddad Wassim
• Halpern Joel

Classifications

• H04L45/22

  Alternate routing · CPC title

• H04W24/04 Primary

  Arrangements for maintaining operational condition · CPC title

• H04L41/0668 Primary

  by dynamic selection of recovery network elements, e.g. replacement by the most appropriate element after failure · CPC title

• H04L45/28

  using route fault recovery · CPC title

• H04L69/40

  for recovering from a failure of a protocol instance or entity, e.g. service redundancy protocols, protocol state redundancy or protocol service redirection (management of faults, events, alarms or notifications in data switching networks H04L41/06) · CPC title