SDN Controller Proxy for VM Cross-Data Center Routing
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Solution Overview
Problem
Existing network communication methods between virtual machines across data centers result in high transmission bandwidth usage and roundabout routing due to broadcasted ARP requests and the need for packets to pass through multiple routers.
Innovation Solution
A method where a first switch acquires the MAC address of a destination virtual machine, obtains VTEP information corresponding to this MAC address, and sends IP packets through a tunnel between switches, with an SDN controller acting as a proxy to reduce bandwidth usage and bypass unnecessary router traversal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If ARP requests are broadcast to each VM to acquire MAC addresses, then VMs can communicate across data centers, but transmission bandwidth is heavily occupied
Solution Approach 1:
The patent introduces an SDN controller as an intermediary to handle ARP requests. Instead of broadcasting ARP requests to all VMs, the SDN controller receives the ARP request, queries the MAC address from its forwarding table, and returns the result. This mediator approach eliminates widespread broadcasting while maintaining communication capability.
Solution Approach 2:
The patent extracts the ARP resolution function from the broadcast domain and relocates it to the SDN controller. By separating the ARP query function from the data plane, the system eliminates the need for broadcast ARP requests across the network while preserving the ability to resolve MAC addresses.
2Reliability
If packets pass through routers in each data center to reach destination VMs, then communication between data centers is established, but routing becomes roundabout and inefficient
Solution Approach 1:
The patent introduces a new routing dimension by establishing direct tunnels between switches in different data centers. Instead of the traditional hierarchical path through multiple routers, the system creates a direct overlay network path that bypasses intermediate routing infrastructure, effectively adding a new dimensional route.
Solution Approach 2:
The patent extracts packets from the traditional router-based forwarding path and redirects them through direct switch-to-switch tunnels. By removing packets from the conventional routing path and placing them in a dedicated tunnel, the system eliminates unnecessary router traversals and achieves more efficient direct communication.
3Adaptability or versatility
If multiple routers are traversed for inter-data center communication, then comprehensive routing coverage is achieved, but device complexity and communication overhead increase
Solution Approach 1:
The patent merges multiple router functions into a single tunnel endpoint function. By combining the routing, forwarding, and tunnel termination functions at the tunnel endpoints, the system reduces the number of discrete devices packets must traverse while maintaining comprehensive routing coverage through the tunnel network.
Data Source
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AI summary
In a method and an apparatus provided in embodiments of the present invention, a first switch receives an ARP response from an SDN controller, where the ARP response carries a MAC address of a destination gateway; the first switch acquires, according to the MAC address of the destination gateway, VTEP information corresponding to the MAC address of the destination gateway, where a router corresponding to the VTEP information is located in a first data center; and the first switch sends, according to the VTEP information, an IP packet to the router corresponding to the VTEP information, so that the router corresponding to the VTEP information sends the IP packet to a second virtual machine through a tunnel between the router and a second switch. Therefore, an SDN controller serves as a proxy, which reduces transmission bandwidth occupied by packet broadcasting; in addition, a packet passes only through a router of the first data center, which alleviates roundabout routing of the packet between data centers.