Segment Routing Interworking via Binding Segment Identifiers

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Solution Overview

Problem

Current packet switching networks face challenges in interworking between heterogeneous forwarding domains using different data plane protocols, such as Segment Routing (SRv6) and Multiprotocol Label Switching (SR-MPLS), which hinders efficient packet forwarding and service delivery across diverse network topologies.

Innovation Solution

The implementation of a network architecture that determines and modifies paths between domains by installing Binding Segment Identifiers (BSIDs) and forwarding policies, allowing packets to traverse different data plane protocols without conversion, using techniques like BGP Labeled Unicast and Segment Routing headers, enabling seamless interworking between SRv6 and SR-MPLS domains.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If packets are forwarded through gateway nodes that convert between different data plane protocols (SRv6 and SR-MPLS), then interoperability between heterogeneous forwarding domains is achieved, but packet forwarding efficiency deteriorates and additional protocol conversion overhead is introduced

Engineering Contradiction:
Improveinteroperability between heterogeneous forwarding domainsVSAvoidpacket forwarding efficiency
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent introduces Binding Segment Identifiers (BSIDs) as intermediary elements that enable direct communication between SRv6 and SR-MPLS domains without requiring protocol conversion at gateway nodes. The BSID acts as a mediator that allows packets to traverse heterogeneous domains while maintaining their original protocol format, thus eliminating conversion overhead and improving forwarding efficiency while preserving interoperability

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If protocol conversion gateways are deployed to enable communication between SRv6 and SR-MPLS domains, then network connectivity between different forwarding domains is achieved, but network complexity increases

Engineering Contradiction:
Improvenetwork connectivity between forwarding domainsVSAvoidnetwork complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent extracts the protocol conversion function from traditional gateway nodes and replaces it with BSID-based direct routing. By removing the need for protocol conversion gateways and their associated conversion logic, the network complexity is reduced while maintaining connectivity between SRv6 and SR-MPLS domains through the BSID intermediary mechanism

Inventive Principle:
Principle #2Taking out (Extraction)

3Ease of operation

If traditional routing protocols are used without BSID modification, then simple routing is maintained, but traffic engineering capabilities across heterogeneous domains are insufficient

Engineering Contradiction:
Improverouting simplicityVSAvoidtraffic engineering capabilities
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The patent applies preliminary action by pre-computing and installing BSID-based forwarding policies in the routing tables before packet transmission. This allows the network to maintain simple routing operations at runtime while having sophisticated traffic engineering capabilities embedded in the pre-configured BSID paths, enabling both routing simplicity and enhanced traffic engineering

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3871380B1Packet network interworking including segment routing
Publication Date: 2024.03.13 CISCO TECHNOLOGY INC
  • EP3871380B1 patent drawingFigure 1A~1B
  • EP3871380B1 patent drawingFigure 1C~1D
  • EP3871380B1 patent drawingFigure 2A

AI summary

In one embodiment, a network comprises a first forwarding domain using a first data plane forwarding protocol and a second forwarding domain using a second data plane forwarding protocol different than the first data forwarding plane forwarding protocol. The first forwarding domain includes a first path node and a particular border node. The second forwarding domain includes a second path node and the particular border node. The particular border node performs Segment Routing or other protocol interworking between the different data plane forwarding domains, such as for transporting packets through a different forwarding domain or translating a packet to use a different data forwarding protocol. These forwarding domains typically include Segment Routing (SR) and SR-Multiprotocol Label Switching (SR-MPLS). Paths through the network are determined by a Path Computation Engine and/or based on route advertisements such associated with Binding Segment Identifiers (BSIDs) (e.g., labels, Internet Protocol addresses).