DHCP Server MAC Address Translation for Roaming IP Continuity

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Solution Overview

Problem

In data communication networks, wireless network extenders cause communication disruptions when client devices roam from areas covered by extenders to areas covered only by access points, due to MAC address translation issues leading to IP address changes and data collisions, resulting in IP session discontinuity and access control problems.

Innovation Solution

A method and system for allocating Internet Protocol addresses in networks that involves MAC address translation, verification of translated addresses, and announcement messages to ensure IP address continuity and compatibility with MAC filtering, using a processor and network interface to manage IP address allocation and MAC address translations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If MAC address translation is applied by the wireless network extender, then data collisions are avoided in common coverage areas, but IP session continuity is disrupted when client devices roam between extender and access point coverage areas

Engineering Contradiction:

Improvedata communication reliabilityVSAvoidIP session continuity

Core Design Contradiction:

ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The DHCP server acts as an intermediary that receives DHCP requests from roaming client devices, translates their real MAC addresses to translated MAC addresses, and retrieves the corresponding IP addresses from its records. This intermediary translation mechanism allows the DHCP server to maintain IP session continuity even when the client device moves between coverage areas and its MAC address representation changes.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The system changes the MAC address parameter from the real MAC address to the translated MAC address in the DHCP request. This parameter transformation allows the DHCP server to identify the roaming client device through its translated MAC address and allocate the same IP address, thereby maintaining IP session continuity during roaming.

Inventive Principle:

Principle #35Parameter changes

2Device complexity

If a single DHCP server is used in the network, then network configuration is simplified, but the DHCP server cannot properly handle IP address allocation for roaming devices that use translated MAC addresses

Engineering Contradiction:

Improvenetwork configuration complexityVSAvoidDHCP server adaptability to roaming devices

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The DHCP server performs preliminary actions by maintaining a record of translated MAC addresses and their corresponding real MAC addresses and IP addresses. When a roaming client device sends a DHCP request with its translated MAC address, the DHCP server can proactively retrieve the associated IP address from its records, enabling it to handle roaming devices effectively while maintaining a single-server configuration.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The DHCP server uses feedback from the translated MAC address in the DHCP request to identify the roaming client device and retrieve its previously allocated IP address. This feedback mechanism allows the single DHCP server to adapt to roaming devices by using the translated MAC address as a key to access the device's network identity information.

Inventive Principle:

Principle #23Feedback

3Area of stationary object

If wireless network extenders are deployed to improve coverage, then areas with poor signal are covered, but data collisions occur in common coverage areas due to duplicate MAC address responses

Engineering Contradiction:

Improvewireless network coverage areaVSAvoiddata communication reliability

Core Design Contradiction:

Area of stationary objectVSReliability

Solution Approach 1:

The wireless network is segmented into multiple coverage areas served by different access points and extenders. Each extender creates a separate network segment for devices connected to it, using MAC address translation to distinguish devices in its segment from devices directly connected to the main access point. This segmentation prevents data collisions in common coverage areas while maintaining extended coverage.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS10171414B2Method for allocating internet protocol addresses to clients of a network and corresponding apparatus

Publication Date: 2019.01.01 INTERDIGITAL CE PATENT HOLDINGS SAS

AI summary

An access device and an extender access device, forming a network for network client devices. A single IP address attribution server in the network attributes IP addresses to network devices based on their MAC address. The access device providing access in a first coverage zone. The extender access device providing access in a second coverage zone. The extender access device implements MAC address translation for representing network client devices in the second zone before the access device. When a network client device roams from the second zone to the first zone, the client device keeps its IP address that was attributed to it by the IP address attribution server via the extender access device even if the client device requests an IP address with its real, non-translated MAC address.