Multi-chassis Router Optical Interconnects

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Solution Overview

Problem

Service providers face challenges in meeting increasing bandwidth demands due to limitations in multi-chassis routers, particularly with centralized switch fabrics and physical constraints related to cable connectors and chassis space.

Innovation Solution

The use of fiber-optic cables with optical taps and wavelength filters to connect multiple routing nodes, allowing for multiplexed optical interconnects that distribute optical power equally among nodes, reducing the need for centralized switch fabrics and minimizing physical complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If centralized switch fabrics are used in multi-chassis routers, then routing control is simplified, but physical complexity and space requirements increase

Engineering Contradiction:

Improverouting controlVSAvoidphysical complexity

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The patent segments the centralized switch fabric function into distributed switch fabric portions located at each routing node. Each routing node independently performs switching operations, eliminating the need for a large centralized switch fabric while maintaining routing control capabilities through distributed intelligence.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent transitions from a centralized spatial arrangement to a distributed network topology where routing nodes are connected via optical interconnects. This dimensional change allows routing control to be maintained while physical complexity is reduced through optical rather than electrical interconnections.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Power

If more cable connectors are added to support higher bandwidth, then bandwidth capacity increases, but physical space and chassis constraints are exceeded

Engineering Contradiction:

Improvebandwidth capacityVSAvoidchassis space

Core Design Contradiction:

PowerVSArea of stationary object

Solution Approach 1:

The patent replaces traditional electrical cable connectors with optical interconnects. This substitution enables higher bandwidth capacity through optical fibers while requiring fewer physical connectors and less chassis space, as optical interconnects can carry multiple wavelengths of data simultaneously through wavelength division multiplexing.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the physical medium from electrical to optical, fundamentally altering the bandwidth-capacity relationship. Optical interconnects provide exponentially higher bandwidth per connector compared to electrical connectors, allowing bandwidth capacity to increase without proportionally increasing physical space requirements.

Inventive Principle:

Principle #35Parameter changes

3Adaptability or versatility

If optical power is distributed to multiple routing nodes, then network connectivity is improved, but signal loss increases

Engineering Contradiction:

Improvenetwork connectivityVSAvoidsignal loss

Core Design Contradiction:

Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The patent introduces optical amplifiers or regenerators as intermediary devices along the optical paths between routing nodes. These intermediaries compensate for signal loss by amplifying or regenerating optical signals, enabling long-distance distribution of optical power to multiple routing nodes while maintaining signal integrity and improving overall network connectivity.

Inventive Principle:

Principle #24Intermediary (Mediator)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach enables scalable multi-chassis routers without bandwidth limitations, reduces physical complexity, and increases space for external interfaces, allowing for more efficient network connectivity.

Implementation Method 1

a plurality of optical taps (283, 592) to output a portion (241) of the optical signal to each of the remaining routing nodes; and the plurality of optical taps divide an optical power of the optical signal substantially equally among the remainder of the plurality of routing nodes

Methodology Applied

Scientific EffectOptical power division:

Implementation Method 2

a plurality of wavelength filters (284, 584) to filter the divided optical signal from the optical taps

Methodology Applied

Scientific EffectWavelength filtering: Filter (optical)

Data Source

PatentEP2280515B1Multi-chassis router with multiplexed optical interconnects

Publication Date: 2019.10.09 JUNIPER NETWORKS INC

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AI summary

A multi-chassis network device (120) includes a plurality of nodes (128 A-D) that operate as a single device within the network and a switch fabric (125 A-D) that forwards data plane packets between the plurality of nodes (128 A-D). The switch fabric (125 A-D) includes a set of multiplexed optical interconnects coupling the nodes (128 A-D). For example, a multi-chassis router (120) includes a plurality of routing nodes (128 A-D) that operate as a single router within a network and a switch fabric (125 A-D) that forwards packets between the plurality of routing nodes (128 A-D). The switch fabric (125 A-D) includes at least one multiplexed optical interconnect coupling the routing nodes (128 A-D). The nodes (128 A-D) of the multi-chassis router (120) may direct portions of the optical signal over the multiplexed optical interconnect to different each other using wave-division multiplexing.