Method for Client Data Transmission Through a Packet Switched Provider Network

• US 20120020206A1
• Filed: 04/01/2010
• Published: 01/26/2012
• Est. Priority Date: 04/16/2009
• Status: Active Grant

• Current Assignee: RPX Corporation
• Original Assignee: Alcatel-Lucent SA (Nokia Corporation)
• Inventors: Busi, Italo, Addeo, Christian
• Granted Patent: US 9,172,630 B2
• Time in Patent Office: Days
• US Class Current: 370/217
• CPC Class Codes: H04L 41/00 Arrangements for maintenance, administration or management of data switching networks, e.g. of packet switching networks
• CPC Class Codes: H04L 41/12 Discovery or management of network topologies
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 45/02 Topology update or discovery
• CPC Class Codes: H04L 45/021 Ensuring consistency of routing table updates, e.g. by using epoch numbers
• CPC Class Codes: H04L 45/18 Loop-free operations
• CPC Class Codes: H04L 45/22 Alternate routing
• CPC Class Codes: H04L 45/26 Route discovery packet
• CPC Class Codes: H04L 45/28 using route fault recovery
• CPC Class Codes: H04L 45/36 Backward learning
• CPC Class Codes: H04L 45/66 Layer 2 routing, e.g. in Ethernet based MAN's
• CPC Class Codes: H04L 45/741 Routing in networks with a plurality of addressing schemes, e.g. with both IPv4 and IPv6

Abstract

In order to provide a redundancy mechanism in a packet switched provider network, which allows faster recovery from a failure, it is proposed that in case of a failure, a redundancy mechanism is initiated to reroute packet transmission through the provider network via an alternate path and an address withdrawal message is sent to network nodes along the failed path using data plane protocol. A network node receiving the address withdrawal message will flush MAC addresses it had learned before.

Claims

1. A method of client data transmission through a packet switched provider network;

the method comprising the steps of;

providing packet transmission along a first path through said provider network;

at one or more network nodes along said first path, performing address learning to allow packet transmission in reverse direction along the same first path;

protecting said first path by a redundant second path using a redundancy mechanism;

in case of a failure at said first path;

initiating said redundancy mechanism to reroute packet transmission through said provider network via said second path; and

after initiating said redundancy mechanism, sending to said one or more network nodes that have performed address learning an address withdrawal message using a data plane protocol; and

responsive to receiving said address withdrawal message, flushing addresses previously learned at the receiving network node.

2. A method according to claim 1, wherein said redundancy mechanism is an edge redundancy mechanism.

3. A method according to claim 1, wherein a status change of said redundancy mechanism is detectable only at a customer edge node and wherein said customer edge node creates said address withdrawal message and sends it to a provider edge node via an access link.

4. A method according to claim 1, wherein a status change of said redundancy mechanism is detectable at a provider edge node and wherein said provider edge node creates said address withdrawal message and sends it towards a far end provider edge node.

5. A method according to claim 1, wherein said address withdrawal message is an Ethernet protocol frame.

6. A method according to claim 5, wherein said Ethernet protocol frame includes said address withdrawal message in the form of an Ethernet OAM message.

7. A method according to claim 1, wherein only provider edge nodes perform said address learning and address flushing steps.

8. A method according to claim 1, wherein said provider network is directly managed by a central network management instance.

9. A network element of a packet switched provider network;

comprising input and output interfaces for providing packet transmission along a path through said provider network;

packet switching means for switching packet traffic in accordance with address information contained in each packet, wherein said packet switching means are adapted to perform address learning to allow packet transmission in reverse direction along the same path and wherein said packet switching means are further adapted to flush addresses previously learned upon reception of a data plane control message containing an address withdrawal message.