Atomic Host Route Installation for Mobile VPN Roaming
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Mobile nodes experience packet loss and routing loops when roaming between wireless local area networks (WLAN) and cellular networks due to non-atomic host route installation and withdrawal, which disrupts seamless IP address preservation and traffic policies.
Innovation Solution
Implementing atomic host route installation and withdrawal techniques in mobile virtual private networks (VPN) that delay upstream router programming until downstream routers have converged, ensuring seamless network connectivity and avoiding routing loops by using timing information to coordinate route changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If non-atomic host route installation and withdrawal is used, then routing updates can be propagated quickly, but packet loss and routing loops occur during mobile node roaming
Solution Approach 1:
The patent applies preliminary action by installing host routes in downstream routers before upstream routers. This ensures that when a mobile node roams to a new access network, the forwarding path is already prepared at lower levels of the routing hierarchy before upper levels are updated, preventing packet loss and routing loops while maintaining fast propagation
Solution Approach 2:
The routing update process is segmented into multiple phases: first updating downstream routers (closer to mobile nodes), then progressively updating upstream routers (farther from mobile nodes). This segmentation allows controlled propagation of routing changes without causing network-wide disruptions
2Reliability
If atomic host route installation is implemented, then packet loss and routing loops are prevented, but route installation complexity increases
Solution Approach 1:
The patent introduces timing information as an intermediary mechanism that coordinates route installation across multiple routers. This timing information acts as a mediator that synchronizes the atomic installation process without requiring complex inter-router communication protocols, thus achieving reliability while controlling complexity
Solution Approach 2:
The patent changes the timing parameter of route installation by introducing delay intervals and sequencing mechanisms. By controlling when routes are installed at different router levels through parameter adjustment, atomic installation is achieved without requiring fundamental changes to the routing protocol structure
3Speed
If host routes are installed in upstream routers before downstream routers, then routing updates propagate faster, but routing loops and packet loss occur
Solution Approach 1:
The patent reverses the conventional approach by performing preliminary action at downstream routers first. Before upstream routers install host routes, downstream routers are pre-configured with the new routing information, ensuring that packets will have valid forwarding paths when the upstream routers are updated, thus preventing routing loops and packet loss
Data Source
AI summary
In general, techniques are described for atomically installing and withdrawing host routes along paths connecting network routers to attenuate packet loss for mobile nodes migrating among wireless LAN access networks and a mobile network. In some examples, whenever the mobile node moves from one attachment point to the next, it triggers the distribution of its host route from the new attachment point toward the service provider network hub provider edge (PE) router that anchors the mobile node on a service provider network. Routers participating in the Mobile VPN install the host route “atomically” from the attachment point to the mobile gateway so as to ensure convergence of the network forwarding plane with the host route toward the new attachment point prior to transitioning mobile node connectivity from a previous attachment point.