Virtually Located DNS Resolver for CDN Surrogate Selection

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Solution Overview

Problem

Content Delivery Networks (CDNs) often fail to accurately select a nearby CDN surrogate due to the inability to determine the client's actual location in the network, leading to poor performance, higher network costs, and unsatisfactory user experiences.

Innovation Solution

A method and apparatus that enable the selection of a remote service node by using a 'Virtually Located DNS Resolver' (VLDR) which selects a virtual IP address based on the client's IP address, network topology, and cost information, allowing for intelligent surrogate selection without modifying the DNS protocol or requiring standardization, and allowing the ISP to manage network costs and load balancing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If DNS resolver uses client's actual IP address to select CDN surrogate, then surrogate selection accuracy improves, but network cost information and topology details must be exposed to CDN

Engineering Contradiction:
Improvesurrogate selection accuracyVSAvoidnetwork cost information exposure
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The patent introduces a intermediary mapping mechanism where the DNS resolver translates the client's actual IP address into a virtual IP address that represents a specific network location or region. This virtual IP address is then used for CDN surrogate selection, allowing the DNS resolver to convey location information to the CDN without exposing detailed network topology or cost information. The intermediary layer preserves selection accuracy while protecting sensitive network data.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of manufacture

If CDN uses centralized DNS resolver, then DNS infrastructure cost reduces, but surrogate selection performance deteriorates due to inability to determine client location

Engineering Contradiction:
ImproveDNS infrastructure costVSAvoidsurrogate selection performance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent changes the parameter used for surrogate selection from the client's actual IP address to a virtual IP address that encodes network location information. The DNS resolver selects appropriate virtual IP addresses based on the client's actual location and network conditions. This parameter transformation allows a centralized DNS resolver to achieve location-aware surrogate selection without requiring distributed DNS infrastructure, thus maintaining cost efficiency while improving selection performance.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If virtual DNS resolver locations are deployed physically, then selection accuracy improves, but deployment time and complexity increases

Engineering Contradiction:
Improvelocation determination accuracyVSAvoiddeployment time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent creates virtual copies of DNS resolver locations through virtual IP addresses rather than deploying physical DNS resolver instances at every possible client location. Each virtual IP address represents a logical network location that can be mapped to actual CDN surrogate regions. This virtualization approach allows rapid deployment of location-aware DNS resolution without the time-consuming process of physically distributing DNS infrastructure across multiple sites.

Inventive Principle:
Principle #26Copying

Data Source

PatentEP2695358B1Selection of service nodes for provision of services
Publication Date: 2018.04.18 BRITISH TELECOM PLC
  • EP2695358B1 patent drawingFigure 1
  • EP2695358B1 patent drawingFigure 2
  • EP2695358B1 patent drawingFigure 3

AI summary

Methods and apparatus are disclosed for enabling selection of a remote service node from a plurality of possible nodes, each capable of providing a service, and each associated with a service node control entity. The method comprises: receiving a user request in respect of a service required by a user, the request containing a first user device routing identifier relating to the location in the network of the user device, and a service indication indicative of an appropriate service provider; identifying from the service indication a service node control entity associated with the service provider; sending to the service node control entity a service node request containing a second user device routing identifier differing from the first user device routing identifier but selected at least partly in dependence thereon; receiving from the service node control entity an indication of a remote service node capable of providing the required service; and providing an indication of the remote service node to the user device.