Overlay Tunnel Load Balancing via Traffic Entropy Capture
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Solution Overview
Problem
Network traffic polarization occurs when using overlay tunnels, leading to overutilization of certain paths or links, causing network delay, latency, or packet loss due to identical packet header information, which existing load balancing techniques fail to effectively address.
Innovation Solution
Intermediary devices capture traffic entropy by analyzing LAN traffic flow information, including source ports, to differentiate packet flows and route them via different paths, reducing polarization and improving load balancing efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If overlay tunnels are used to provide virtual paths for network traffic, then network traffic can be encapsulated and transmitted between networking devices, but all traffic between a pair of networking sites is assigned the same packet header information, leading to polarization of network traffic on a particular path and overutilization of certain links
Solution Approach 1:
The patent segments the packet header information by capturing and utilizing the source port field, which is otherwise unused in overlay tunnel encapsulation. This segmentation allows differentiation of traffic flows that would otherwise have identical headers, enabling load balancers to distribute traffic across multiple paths effectively.
Solution Approach 2:
The patent changes the parameter used for load balancing from the traditional 5-tuple (source IP, destination IP, source port, destination port, protocol) to include the overlay source port, creating a 6-tuple. This parameter change allows the load balancer to distinguish between different traffic flows within the same overlay tunnel, preventing traffic polarization.
2Ease of operation
If load balancing is performed using hash calculation on packet headers, then network paths can be selected based on traffic patterns, but packets with the same or similar header information result in traffic polarization on a particular path
Solution Approach 1:
The patent performs preliminary action by capturing and storing the source port information from the inner packet header before the hash calculation is performed. This pre-capture ensures that the load balancer has access to sufficient entropy in the packet header to generate diverse hash values, preventing traffic polarization while maintaining ease of operation.
Solution Approach 2:
The source port field acts as an intermediary element that bridges the gap between overlay tunnel encapsulation and load balancing requirements. By utilizing this intermediate field, the system can maintain simple overlay tunnel operation while achieving reliable traffic distribution across multiple paths.
3Device complexity
If the same packet header information is used for all traffic in an overlay tunnel, then encapsulation is simplified, but network delay, latency, or packet loss occurs due to overutilization of certain paths
Solution Approach 1:
The patent extracts the source port information from the inner packet header, which would otherwise be discarded during overlay tunnel encapsulation. This extraction adds minimal complexity to the encapsulation process while enabling effective load balancing that prevents path overutilization and reduces network delay and latency.
Data Source
AI summary
Disclosed embodiments describe systems and methods for tunneling packets. A tunnel between a first intermediary device and a second intermediary device is established that encapsulates payload packets of transport layer connections between a client and a server. The first intermediary device identifies, from a first packet of a transport layer connection between the client and the server, packet header information. The first intermediary device populates a destination port and a source port of a header of a second packet to be transmitted via the tunnel. The destination port is populated with a predetermined destination port, and the source port includes a first hash of a tuple of the packet header information of the first packet. The second packet includes the first packet as a payload, and is load balanced across paths to the second intermediary device based on a second hash of the header of the second packet.