# US 8,787,398 B2 · Linear route protection

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- Number: US 8,787,398 B2
- Document ID: US8787398B2
- Status: Granted
- Kind: B2
- Application number: 13/388,780
- Filed: 2009-07-31
- Published: 2012-11-08
- Granted: 2014-07-22
- Earliest claimed: 2009-07-31
- Assignees: Ciena Corporation
- Applicants: Marc Holness; Bashar Abdullah; Marc-Andre Rochon; Simon Parry; Chris Ramsden
- Inventors: Marc Holness; Bashar Abdullah; Marc-Andre Rochon; Simon Parry; Chris Ramsden
- Web page: https://patentgrep.com/patent/US8787398B2

## CPC

- H04L 12/437: Ring fault isolation or reconfiguration {(for SDH/SONET ring networks H04J3/085)}
- H04L 45/28: using route fault recovery
- H04L 45/50: using label swapping, e.g. multi-protocol label switch [MPLS]
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)

## Abstract

A system for controlling packet forwarding through a point-to-point (p2p) connection between first and second end nodes of a packet network domain having a mesh topology. The system comprises a sub-ring network instantiated in the network domain, the sub-ring network comprising a pair of topologically diverse ring spans extending between the first and second end nodes. Each of the end nodes is controlled to forward packets of the p2p connection through the sub-ring network in accordance with a ring network routing scheme, and an intermediate node traversed by one of the ring spans is controlled to forward packets of the p2p connection through the ring span in accordance with a linear path routing scheme.

## Claims

### Claim 1

A system for controlling packet forwarding through a point-to-point (p2p) connection between first and second end nodes of a packet network domain having a mesh topology, the system comprising:
a sub-ring network instantiated in the network domain, the sub-ring network comprising a pair of topologically diverse ring spans extending between the first and second end nodes;
wherein each of the end nodes is controlled to forward packets of the p2p connection through the sub-ring network in accordance with a ring network routing scheme, and an intermediate node traversed by one of the ring spans is controlled to forward packets of the p2p connection through the ring span in accordance with a linear path routing scheme comprising a G.8032 Ethernet ring protocol adapted to operate on the pair of topologically diverse ring spans that do not form a proper G.8032 ring.

### Claim 2 (depends on 1)

The system as claimed in claim 1, wherein at least one of the end-nodes is designated as a Ring Protection Link Owner, and is controlled to impose a channel block to prevent forwarding of traffic of the sub-ring network through a selected one of the ring spans.

### Claim 3 (depends on 1)

The system as claimed in claim 1, wherein the network domain is any one of an Ethernet domain, an IP domain, a Provider Backbone Transport (PBT) domain, a Multi-Protocol Label Switching (MPLS) domain, and a Virtual Private LAN Service (VPLS) domain.

### Claim 4 (depends on 2)

The system as claimed in claim 2, wherein one span of the sub-ring network is designated as a Ring Protection Span, and wherein respective channel blocks are imposed at opposite ends of the Ring Protection Span.