Link Aggregation With Receive-Side Buffering for Flow Ordering

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Solution Overview

Problem

Existing link aggregation methods face challenges such as complexity, inefficient utilization of bandwidth, and quality of service (QoS) issues due to biased link assignment and temporary congestion, particularly in scenarios with varying link bandwidths.

Innovation Solution

A communication arrangement that identifies data flows and attaches independent sequence numbers to data segments, selects communication links based on availability, and maintains flow identity tables to manage link aggregation efficiently, allowing data segments to be forwarded on any link without reordering within individual flows.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If L1 bonding is used to aggregate links with different rates, then spectrum efficiency is improved, but device complexity increases due to strict control requirements for delivery order and complex buffering schemes

Engineering Contradiction:
Improvespectrum efficiencyVSAvoidbuffering and reassembly complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The invention segments the data flow into multiple independent flows, each identified by a flow identity (FI) derived from source and destination addresses. Each flow can be transmitted over different links independently, eliminating the need for complex centralized buffering and reassembly while maintaining delivery order within each flow. This segmentation approach resolves the contradiction by achieving load balancing and spectrum efficiency without requiring complex coordination mechanisms.

Inventive Principle:
Principle #1Segmentation

2Device complexity

If L2/L3 link aggregation is used to simplify implementation, then device complexity is reduced, but bandwidth utilization becomes inefficient due to biased link assignment and temporary congestion

Engineering Contradiction:
Improveimplementation complexityVSAvoidbandwidth utilization
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The invention introduces dynamic link selection where the traffic handling unit can adaptively choose which link to use for each flow based on current link status and utilization. The system maintains flow identity tables that track which flows are assigned to which links, allowing dynamic redistribution of flows to balance load across links. This dynamic approach eliminates the static biased assignment of traditional L2/L3 aggregation, improving bandwidth utilization while keeping implementation complexity low.

Inventive Principle:
Principle #15Dynamics

3Reliability

If flow-based link assignment is used to preserve data segment order, then reliability is improved, but bandwidth utilization decreases due to biased outcomes and overprovisioning

Engineering Contradiction:
Improvedata segment order preservationVSAvoidbandwidth utilization
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The invention creates a universal link aggregation system that can handle multiple flows simultaneously across multiple links. The flow identity table structure allows any flow to be assigned to any available link, and the system universally applies the same rules for maintaining order within flows while allowing flexible distribution across links. This multi-functional approach enables the system to preserve data segment order for all flows reliably while maximizing bandwidth utilization through flexible load distribution.

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

Data Source

PatentEP3747168B1Link aggregation with receive side buffering
Publication Date: 2025.09.24 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3747168B1 patent drawingFigure 1
  • EP3747168B1 patent drawingFigure 2
  • EP3747168B1 patent drawingFigure 3

AI summary

The present disclosure relates to a communication arrangement (110, 130) adapted for link aggregation of a plurality of communication links (120a, 12b, 120c). The communication arrangement (110, 130) is adapted to communicate via the plurality of communication links (120a, 120b, 120c) and comprises a traffic handling unit (112, 132) that is adapted to obtain data segments (414-417, 419-421, 423-425) to be transmitted, and to identify one or more data flows (401, 402, 403, 404) in said data segments. The traffic handling unit is adapted to attach sequence numbers, SEQ, to data segments associated with each identified data flow (401, 402, 403, 404), wherein sequence numbers are independent between data flows and to select a communication link for transmission of a data segment associated with a certain data flow (401, 402, 403, 404). The selecting comprises selecting a previous communication link that has been used for transmission of a previous data segment from said certain data flow (401, 402, 403, 404) if possible, and selecting any communication link otherwise.