SFC Packet Forwarding via BGP Routing Entry Synchronization

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Solution Overview

Problem

The interaction between conventional routing and switching devices and SDN controllers in service function chaining (SFC) is not standardized, leading to difficulties in implementing smooth interconnection due to vendor-specific private extensions, which are not unified.

Innovation Solution

A method is introduced to standardize the interaction between routing and switching devices and controllers by using Border Gateway Protocol (BGP) to synchronize routing entry information, enabling smooth interconnection through the use of service path identifiers (SPI) and service indices (SI) within the SFC framework.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If vendor-specific private extensions are used for hardware improvements in conventional routing and switching devices, then device functionality is enhanced, but interaction standardization with SDN controllers deteriorates

Engineering Contradiction:
Improvedevice functionalityVSAvoidinteraction standardization
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The patent introduces BGP as an intermediary protocol that mediates between the control plane (SDN controller) and data plane (routing and switching devices). By using BGP's standardized path attributes (SPI, SI, service index) as intermediaries, the system achieves standardized interaction without requiring vendor-specific private extensions, thus resolving the contradiction between functionality enhancement and interaction standardization.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If OpenFlow protocol is used for point-to-point forwarding entry delivery, then controller-device communication is established, but interoperability between different vendors deteriorates

Engineering Contradiction:
Improvecontroller-device communicationVSAvoidinteroperability
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The patent makes BGP universally applicable for SFC routing entry synchronization across multi-vendor environments. By leveraging BGP's existing multi-functional capabilities (path selection, policy routing, traffic engineering) and extending them with SFC-specific attributes (SPI, SI), the system achieves vendor-neutral interoperability while maintaining comprehensive controller-device communication functionality.

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

3Productivity

If SFC routing entry synchronization is implemented, then packet forwarding efficiency is improved, but system complexity increases

Engineering Contradiction:
Improvepacket forwarding efficiencyVSAvoidsystem complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent implements preliminary synchronization of SFC routing entries between controllers and routing/switching devices using BGP before actual packet forwarding begins. By pre-establishing the forwarding paths, service path identifiers (SPI), and service indices (SI) through BGP routing updates, the system prepares the data plane in advance, enabling efficient packet forwarding without real-time computation overhead during traffic flow.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3468112B1Method, apparatus and system for forwarding packet in service function chaining (SFC)
Publication Date: 2025.06.25 HUAWEI TECH CO LTD
  • EP3468112B1 patent drawingFigure 1
  • EP3468112B1 patent drawingFigure 2~3
  • EP3468112B1 patent drawingFigure 4~5

AI summary

The present invention discloses a method, an apparatus, and a system for forwarding a packet in SFC, which can standardize interaction between a routing and switching device and a controller, to implement smooth interconnection between the controller and the routing and switching device. The method includes: determining, by a control node, routing entry information of a service function forwarding node in a service function path SFP in the SFC, where the routing entry information records a mapping relationship between route prefix information and next hop information, the route prefix information includes a service path identifier SPI and a service index SI, the SPI is used to identify the SFP, the SI is used to identify a location of the service function forwarding node in the SFP, and the next hop information is used to indicate a next hop node of the service function forwarding node in the SFP; and sending, by the control node, the routing entry information to the service function forwarding node, where the routing entry information is used by the service function forwarding node to generate a forwarding table, and the forwarding table is used to instruct the service function forwarding node to forward a packet.