OpenFlow Switch NAT via Pre-configured Group Tables
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Solution Overview
Problem
In existing Openflow network systems, frequent interactions between the Controller and Openflow switch to transmit flow tables lead to increased data packet forwarding time delays and reduced network transmission efficiency, especially when handling multiple hosts connecting to different servers on the Internet.
Innovation Solution
A NAT implementation system and method where the Controller transmits pre-set flow tables and an improved group table via the Openflow protocol, allowing the Openflow switch to perform address translation based on pre-defined rules, reducing the need for frequent interactions and optimizing data packet forwarding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the Controller transmits flow tables to the Openflow switch every time a host connects to a different server, then the address translation can be established correctly, but the interaction frequency between Controller and Openflow switch increases, prolonging data packet forwarding time delay
Solution Approach 1:
The patent applies preliminary action by pre-configuring flow tables with multiple server destination rules in advance. When a host connects to any server, the pre-configured flow tables are directly applied without requiring the Controller to transmit new flow tables for each server connection. This eliminates the repeated interaction between Controller and Openflow switch, reducing forwarding time delay while maintaining correct address translation.
2Adaptability or versatility
If the Controller frequently transmits flow tables to handle multiple host connections, then all address translation requests can be fulfilled, but the network transmission efficiency is reduced due to increased interaction overhead
Solution Approach 1:
The patent applies universality by designing flow tables that serve multiple purposes: they handle address translation for multiple different servers and multiple hosts simultaneously. The pre-configured flow tables contain rules for various destination servers, allowing a single set of flow tables to accommodate diverse connection scenarios without requiring separate configurations for each server-host pair, thus maintaining adaptability while reducing interaction overhead.
3Measurement precision
If the Openflow switch waits for flow table updates from the Controller for each new connection, then accurate address translation is ensured, but the data packet forwarding speed is reduced
Solution Approach 1:
The patent applies preliminary action by pre-configuring comprehensive flow tables that include address translation rules for multiple servers before any host connections are established. When data packets arrive, the Openflow switch can immediately apply these pre-configured rules without waiting for Controller updates, ensuring both accurate address translation and fast forwarding speed.
Data Source
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AI summary
Disclosed is an NAT implementation system, comprising: a controller and an Openflow switch. The Controller delivers a flow table and an improved group table. The Openflow switch receives the flow table and the improved group table, and matches, according to an address translation matching rule recorded in the flow table, a data packet that address translation needs to be performed on; and performs translation between a private address and a public IP address according to an address translation rule recorded in the improved group table, and sends the data packet out by using an address after translation. Further disclosed are an NAT implementation method and Openflow switch. By using the present invention, the flow table and the improved group table only need to be sent to the Openflow switch at once, and the Openflow switch does not need to frequently interact with the Controller, so that a forwarding delay of the data packet is shortened and the network transmission efficiency is improved.