VRF Routing via Loopback GRE Tunnels

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Solution Overview

Problem

Current methods for routing data packets between Virtual Routing and Forwarding (VRF) instances within a router device require external hardware and introduce latency, scalability issues, and stability concerns, as they necessitate physical interfaces and external devices for configuration.

Innovation Solution

Configuring static routes between internal VRFs using loopback interfaces and Generic Routing Encapsulation (GRE) tunnels within the router device, allowing for routing without external hardware by assigning loopback interfaces as source and destination points for GRE tunnels and using the same routing table for both.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If external hardware and physical interfaces are used for routing between VRF instances, then routing functionality is achieved, but device complexity and latency increase

Engineering Contradiction:
Improverouting functionalityVSAvoidhardware requirements
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent introduces virtual interface objects (loopback interfaces) as intermediaries between VRF instances, replacing the need for external physical hardware. These virtual interfaces act as mediators that enable routing between VRFs through software-based tunneling mechanisms, thereby achieving the same routing functionality without additional physical devices.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the mechanical/physical routing system (external hardware, physical cables, switch devices) with a software-based virtual routing system. By using virtual interface objects and software-defined tunneling protocols, the system eliminates the need for physical hardware while maintaining routing functionality, thus reducing device complexity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If external switch devices and physical interfaces are used for VRF routing, then routing between VRFs is enabled, but latency increases due to back-and-forth traffic

Engineering Contradiction:
Improverouting capabilityVSAvoidrouting latency
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent merges the routing functionality directly into the router device by creating virtual interface objects within the same device. This eliminates the need for external switch devices and physical cable connections, allowing traffic to be routed internally without leaving the router. The merging of routing functions within the device boundary reduces traversal time and eliminates external communication delays.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

Virtual interface objects serve as internal mediators that enable direct communication between VRF instances without external hardware involvement. These virtual intermediaries process routing decisions and forward traffic internally, eliminating the back-and-forth traffic pattern to external switches and reducing overall latency.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If physical interfaces are required for VRF configuration, then routing is possible, but scalability and stability are compromised

Engineering Contradiction:
Improverouting operationVSAvoidscalability
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent creates universal virtual interface objects that can be instantiated multiple times and assigned to different VRF instances without requiring additional physical hardware. These virtual interfaces provide multi-functional capabilities, serving as configurable routing endpoints for any number of VRFs, thereby enhancing scalability and adaptability while maintaining stable routing operations.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP3800841B1A method and an apparatus for routing data packets in a network
Publication Date: 2023.08.02 TELIASONERA AB
  • EP3800841B1 patent drawingFigure 1
  • EP3800841B1 patent drawingFigure 2
  • EP3800841B1 patent drawingFigure 3

AI summary

The embodiments herein relate to a method and a router device (700, 101) for routing data packets using virtual routing and forwarding (VRF). The method includes; configuring (601) a first loopback interface and assigning a first VRF (VRF1); configuring (602) a second loopback interface and assigning a second VRF (VRF2); configuring (603, 604) first and second GRE tunnels and assigning the tunnels to respective VRF; assigning (605, 605) for each GRE tunnel a source and a destination point, configuring (607) source and destination IP addresses of both GRE tunnels to use the same routing table from a routing table of VRF1 or from a routing table of VRF2; configuring (608) a first static to route data packets destined to a network behind VRF2; and configuring (609) a second static route to route data packets destined to a network behind VRF1.