SD-WAN DPI Parameter Alignment via Local-Remote Inspection
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Solution Overview
Problem
Existing SD-WAN solutions face challenges in optimizing packet flow management across distributed networks due to discrepancies in deep packet inspection (DPI) parameters between local and remote inspectors, leading to suboptimal path selection and service quality for specific applications.
Innovation Solution
A method utilizing both local and remote deep packet inspectors to perform DPI operations, generating and comparing DPI parameters, and adjusting forwarding decisions based on discrepancies to improve packet flow management and service quality by modifying path selection and resource allocation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If only local deep packet inspector is used at edge nodes, then device complexity is reduced, but measurement precision of DPI parameters deteriorates
Solution Approach 1:
The DPI inspection function is segmented into local DPI inspectors at edge nodes and remote DPI inspectors at controller clusters. Local inspectors handle initial packet inspection and generate first DPI parameters, while remote inspectors perform secondary inspection and generate second DPI parameters. This segmentation allows the system to maintain low local complexity while achieving high overall measurement precision through coordinated multi-point inspection.
Solution Approach 2:
The controller cluster acts as an intermediary that coordinates between local DPI inspectors and the central SD-WAN control plane. It receives DPI parameter sets from local inspectors, performs additional inspection through remote inspectors, compares results, and resolves discrepancies. This intermediary mechanism enables precise measurement without requiring every edge node to have full inspection capabilities.
2Measurement precision
If remote deep packet inspector is added to perform second DPI operation, then measurement precision of DPI parameters is improved, but device complexity increases
Solution Approach 1:
Different DPI inspection capabilities are assigned to different locations based on their specific qualities and roles. Local edge nodes have basic DPI inspectors for initial inspection, while remote controller clusters have advanced DPI inspectors for secondary inspection and discrepancy resolution. This local quality differentiation optimizes the overall system precision without uniformly increasing complexity at all nodes.
Solution Approach 2:
Local DPI inspectors perform preliminary inspection and generate first DPI parameters before packets reach the remote inspectors. This preliminary action filters and pre-processes traffic, so that remote inspectors only need to perform secondary verification on selected packets, reducing their workload and the overall system complexity while maintaining high measurement precision.
3Reliability
If discrepancies between first and second DPI parameters are resolved by modifying packet flow management, then service quality is improved, but loss of time in forwarding packets increases
Solution Approach 1:
The system performs partial discrepancy resolution by only modifying packet flow management when actual discrepancies affecting service quality are detected. Not all DPI parameter differences trigger flow management changes - only those that impact application performance or path selection. This selective approach improves service quality while minimizing unnecessary packet handling delays.
Solution Approach 2:
The system implements feedback mechanisms where DPI parameter discrepancies are continuously monitored and analyzed. When discrepancies indicate potential service quality issues, the system triggers flow management modifications. This feedback-driven approach ensures that time-consuming modifications are only performed when actually needed to maintain service quality, rather than for every minor parameter variation.
Data Source
AI summary
Some embodiments provide a method for performing deep packet inspection (DPI) for an SD-WAN (software defined, wide area network) established for an entity by a plurality of edge nodes and a set of one or more cloud gateways. At a particular edge node, the method uses local and remote deep packet inspectors to perform DPI for a packet flow. Specifically, the method initially uses the local deep packet inspector to perform a first DPI operation on a set of packets of a first packet flow to generate a set of DPI parameters for the first packet flow. The method then forwards a copy of the set of packets to the remote deep packet inspector to perform a second DPI operation to generate a second set of DPI parameters. In some embodiments, the remote deep packet inspector is accessible by a controller cluster that configures the edge nodes and the gateways. In some such embodiments, the method forwards the copy of the set of packets to the controller cluster, which then uses the remote deep packet inspector to perform the remote DPI operation. The method receives the result of the second DPI operation, and when the generated first and second DPI parameters are different, generates a record regarding the difference.