Virtual Router Indirection Mapping for Scalable VLAN Handling
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Solution Overview
Problem
Current methods for providing virtual router functionality are limited by the size of the VLAN field, lack flexibility, and are not scalable, especially as VLAN usage overlaps and network standards evolve, restricting the number of virtual routers that can be accommodated and requiring obsolete routing table management.
Innovation Solution
A method that forms a key from the VLAN, VMAN, and ingress port fields using an indirection mapping process to generate a virtual router identifier (VRID), allowing for flexible and scalable virtual router configurations by using a table with content and index values to map the key into a VRID, which identifies a specific virtual router configuration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the VLAN field is directly mapped into a routing table identifier, then the routing process is simple and fast, but the number of virtual routers is limited by the size of the VLAN field
Solution Approach 1:
The patent introduces an intermediary data structure (the table with content values and index values) between the VLAN field and the routing table identifier. This intermediary layer allows multiple VLAN values to map to the same routing table through index values, thereby enabling support for more virtual routers than the VLAN field size would normally permit, while maintaining efficient lookup performance.
2Adaptability or versatility
If the VLAN field size is increased to accommodate more virtual routers, then the number of possible virtual routers increases, but the number of routing tables that need to be maintained increases proportionally
Solution Approach 1:
The patent merges multiple VLAN identifiers into a single routing table by using the intermediary data structure. Multiple content values (representing different VLANs) can share the same index value, which in turn maps to the same routing table. This consolidation reduces the total number of routing tables required while still supporting a large number of virtual routers.
3Ease of manufacture
If the VLAN field is used to identify virtual routers, then the system is simple to implement, but it lacks flexibility when VLAN types or formats change
Solution Approach 1:
The patent segments the mapping process into two distinct parts: the intermediary data structure that handles VLAN identifier translation, and the routing table that performs actual routing. This segmentation allows the intermediary layer to adapt to different VLAN formats and types while the routing table remains unchanged, providing both implementation simplicity and flexibility to VLAN format changes.
Data Source
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AI summary
A method of presenting different virtual routers to different end users, classes of service, or packets is provided. An incoming packet is received having a VLAN field and at least one additional field. A key is formed from the VLAN field and at least one other packet field, and mapped into a virtual router identifier (VRID) using an indirection mapping process. The VRID identifies a particular virtual router configuration from a plurality of possible virtual router configurations. A networking device is configured to have the particular virtual router configuration identified by the VRID, and the packet is then forwarded by the configured device.