Edge Router Switching via DHCP Coordination

Solution Overview

Problem

In carrier networks, maintenance and accommodation changes of edge routers can cause communication interruptions and increased load on edge routers due to the application of uRPF, leading to prolonged communication disruptions and pressure on the L2 section during DHCP address re-acquisition.

Innovation Solution

A communication control device and method that acquires information about edge router switching, instructs a DHCP server to induce re-acquisition of IP addresses, and receives notifications for completion, minimizing communication disruptions by coordinating address re-acquisition between the edge control device and DHCP server.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If uRPF is applied to edge routers for security purposes, then security is improved, but communication interruptions occur during edge router maintenance and accommodation changes

Engineering Contradiction:

ImprovesecurityVSAvoidcommunication interruption time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by having the edge control device delete user configuration information from the switching source edge router before physically disconnecting the cable. This preliminary deletion prevents uRPF from blocking communications during the transition period, as the configuration is already removed from the source router before the physical connection is severed.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements beforehand cushioning by establishing a coordinated switching process where the edge control device manages the timing of configuration deletion and cable disconnection. The system cushions against communication interruptions by ensuring configuration is removed from the source router before the physical link is broken, preventing uRPF-related blocking during the transition.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

2Loss of time

If user configuration is deleted from the switching source edge router, then communication interruptions are reduced, but the DHCP binding table update is delayed

Engineering Contradiction:

Improvecommunication interruption timeVSAvoidDHCP binding table update time

Core Design Contradiction:

Loss of timeVSDuration of action of stationary object

Solution Approach 1:

The patent applies preliminary action by having the edge control device delete user configuration information from the switching source edge router before physically disconnecting the cable. This preliminary deletion prevents uRPF from blocking communications during the transition period, as the configuration is already removed from the source router before the physical connection is severed.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback by having the edge control device wait for a notification from the DHCP server indicating that the DHCP binding table has been updated before completing the cable disconnection and configuration deletion process. This feedback mechanism ensures that the DHCP binding table is updated before the source router is fully decommissioned, preventing communication issues.

Inventive Principle:

Principle #23Feedback

3Reliability

If DHCP address re-acquisition is performed after cable disconnection, then IP address is re-obtained, but load on edge routers and L2 section increases

Engineering Contradiction:

ImproveIP address acquisitionVSAvoidload on edge routers and L2 section

Core Design Contradiction:

ReliabilityVSStress or pressure

Solution Approach 1:

The patent applies preliminary action by having the edge control device delete user configuration information from the switching source edge router before physically disconnecting the cable. This preliminary deletion prevents uRPF from blocking communications during the transition period, as the configuration is already removed from the source router before the physical connection is severed.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements beforehand cushioning by establishing a coordinated switching process where the edge control device manages the timing of configuration deletion and cable disconnection. The system cushions against communication interruptions by ensuring configuration is removed from the source router before the physical link is broken, preventing uRPF-related blocking during the transition.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentUS12021830B2Communication control device, communication control method, and communication control program

Publication Date: 2024.06.25 NIPPON TELEGRAPH & TELEPHONE CORP

AI summary

An edge control device includes: an acquisition unit configured to acquire information about switching of an edge router accommodating a user's terminal; an instruction unit configured to instruct a dynamic host configuration protocol (DHCP) server to induce re-acquisition of an internet protocol (IP) address by the user's terminal on the basis of the information about edge router switching acquired by the acquisition unit; and a receiving unit configured to receive, from a DHCP server, a notification that induction of IP address reacquisition is completed.