Communication Switch Source Port Enforcement for AFDX Virtual Links
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Solution Overview
Problem
Conventional data networks, such as those defined by ARINC 664 part 7, are limited in their ability to handle virtual links with multiple source nodes and complex routing scenarios, leading to inefficiencies in frame forwarding and traffic management.
Innovation Solution
A communication switch is developed that supports Avionics Full-Duplex Switched Ethernet (AFDX) protocol, allowing for multiple source nodes per virtual link, implementing implicit pick-first-valid redundancy and traffic policing on a per-virtual link, per-source port basis, with features like destination port vectors and blackout periods to manage redundancy and bandwidth allocation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional data networks use single-source virtual links with multicast addressing, then frame identification is simple, but network flexibility and ability to handle complex routing scenarios are limited
Solution Approach 1:
The patent segments the virtual link identification into multiple components: virtual link identifier (VLan ID), source port identifier, and destination port identifier. This segmentation allows the network to handle multiple source nodes per virtual link while maintaining manageable frame forwarding logic at each switch, resolving the contradiction between network flexibility and forwarding complexity.
Solution Approach 2:
The patent adds a source port dimension to the traditional destination-based virtual link identification. By incorporating source port information into the frame forwarding decision process, the network gains the ability to handle complex multi-source scenarios without overwhelming complexity at any single switch, as each switch only needs to enforce policies for its connected sources.
2Adaptability or versatility
If multiple source nodes are allowed per virtual link, then network versatility improves, but traffic management and error control become more complex
Solution Approach 1:
The patent implements local quality control by allowing each switch to independently enforce traffic policing and error control policies for frames from its connected source nodes. This distributed approach to traffic management reduces overall system complexity compared to centralized control, as each switch only needs to manage traffic from its local sources rather than coordinating with all other switches.
Solution Approach 2:
The patent applies preliminary action by establishing source port-based traffic policing and error control policies before frames are forwarded through the network. This proactive approach to traffic management simplifies subsequent routing decisions, as frames are pre-classified and policy-checked at the source, reducing the burden on intermediate switches.
3Reliability
If strict source port enforcement is implemented, then error control improves, but frame forwarding flexibility decreases
Solution Approach 1:
The patent implements dynamic source port enforcement through the implicit pick-first-valid redundancy mechanism. The system dynamically selects the first valid frame from multiple sources based on arrival time, rather than statically restricting to a single source. This dynamic approach maintains error control by enforcing source port policies while preserving forwarding flexibility through adaptive frame selection.
Solution Approach 2:
The patent uses feedback mechanisms through traffic policing that monitors frame sources and enforces policies based on observed traffic patterns. The system provides feedback to sources about policy violations and adjusts frame forwarding decisions based on this feedback, maintaining both error control and operational flexibility through continuous adaptation.
Data Source
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AI summary
A communication switch comprises a plurality of ports and a processing unit configured to identify source ports and destination ports from the plurality of ports on a per virtual link basis. Each virtual link comprises one or more source ports via which frames are received from one or more source nodes and one or more destination ports via which received frames are forwarded to one or more destination nodes. For at least one virtual link, the processing unit is configured to accept more than one of the plurality of ports as source ports.