Cable Modem Self-Provisioning via Spoofed DNS and DHCP

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Solution Overview

Problem

Current cable operator provisioning methods for cable modems and multimedia terminal adapters are inefficient, requiring manual technician intervention, resource-intensive, and vulnerable to misuse or misconfiguration, leading to service level issues and inventory management problems.

Innovation Solution

A self-provisioning method that uses a DHCP server to determine the activation status of a cable modem or MTA, generates and encrypts a configuration filename, and employs a spoofing DNS server to validate and update the configuration, allowing devices to automatically associate with the correct subscription plan and service levels, reducing the need for manual technician visits and inventory management.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If manual technician provisioning is used, then service activation can be performed, but resource consumption increases and operational efficiency decreases

Engineering Contradiction:
Improveprovisioning efficiencyVSAvoidresource consumption
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The cable modem automatically performs provisioning operations including registering with the DHCP server, downloading configuration files from the TFTP server, and validating service levels without requiring manual technician intervention. The device self-configures by executing the provisioning protocol steps (ranging negotiation, DOCSIS registration, configuration file download) autonomously upon connection to the network.

Inventive Principle:
Principle #25Self-service

2Ease of operation

If configuration files are stored with human-readable names, then ease of configuration is improved, but security decreases due to vulnerability to misuse

Engineering Contradiction:
Improveconfiguration easeVSAvoidservice level security
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The system performs preliminary validation of service levels and configuration parameters before finalizing the provisioning process. The DHCP server validates the configuration file contents and service level parameters before allowing the cable modem to activate, preventing unauthorized access to higher service plans. The spoofing DNS server also performs preliminary checks to ensure proper service level assignment.

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If technician visits are required for validation, then service level accuracy is improved, but time consumption increases

Engineering Contradiction:
Improveservice level validation accuracyVSAvoidactivation time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent replaces the mechanical system of technician visits with automated electronic validation processes. The DHCP server and spoofing DNS server perform service level validation through automated protocol exchanges and configuration file verification, eliminating the need for physical technician presence while maintaining validation accuracy. The automated system checks service levels, validates configuration parameters, and confirms proper activation remotely.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentEP3382988B1Method for self-provisioning of cable modems and multimedia terminal adapters
Publication Date: 2021.05.05 INTRAWAY R&D SA
  • EP3382988B1 patent drawingFigure 1
  • EP3382988B1 patent drawingFigure 2
  • EP3382988B1 patent drawingFigure 3

AI summary

An unregistered cable modem is in a cable operator network having a computer, a dynamic host configuration protocol (DHCP) server, a spoofing domain name system (DNS) server and a good DNS server, a captive portal application, and a trivial file transfer protocol (TFTP) server. The cable modem is provisioned by the cable modem obtaining a configuration, rebooting, and activating the configuration. The computer obtains a plurality of computer configuration parameters including an IP address of the spoofing DNS. The spoofing DNS server answers an HTTP request from the computer with an IP address associated with the captive portal application. The captive portal obtains an activation code from the computer, verifies the activation code is correct, and forces the cable modem to reboot.