Microsoft Technology Licensing, LLC

Shivakumar Thangapandi

Abhishek Gupta

Vikrant Arora

Deepak Narula

Mohit Kumar Garg

Abhishek Tiwari

Ashok Kumar Nandoori

Ning Wei

Amit Kumar Nanda

Akshat Kale

Amol Wate

Nilambari Narayan Deshpande

Simran Rajkumar Nagrani

Arun Venkatachalam

The techniques described herein increase the throughput of a single VPN connection by creating multiple outbound and/or inbound Security Associations (SAs). For instance, two or more different SAs can encrypt outbound data packets to be sent over the VPN connection to a remote device. Moreover, two or more different SAs can decrypt inbound data packets received over the VPN connection from the remote device. Each of the SAs can be bound to a different processing core via the use of a Security Parameter Index (SPI) identifier. Consequently, inbound data packets communicated over a single VPN connection from a remote device to a physical host in a VPN gateway can be distributed amongst multiple processing cores for decryption purposes. Further, outbound data packets to be communicated over the single VPN connection from the physical host to the remote device can be distributed amongst multiple processing cores for encryption purposes.

Throughput for a single VPN connection using multiple processing cores

A virtual private network (VPN) gateway selects a VPN connection, from multiple VPN connections established between a network VPN gateway and a remote VPN gateway, based on performance factors such as throughput. A system may measure throughput in megabytes per second (Mbps). More specifically, a VPN gateway (e.g., a remote VPN gateway or a network VPN gateway) can configure a routing preference that selects a VPN connection that is more performant based on a cryptographic algorithm that is used for the VPN connection. The VPN gateway can update the routing preference to select an alternative VPN connection when the performance of the VPN connection suffers.

Selecting a VPN connection using negotiated cryptographic algorithms to improve throughput

The techniques described herein enable the establishment of two simultaneous virtual private network (VPN) connections for a VPN client operating on a remote computing device. The VPN client can establish first VPN connection with a first VPN server instance of a VPN gateway and a second VPN connection with a second VPN server instance of the VPN gateway. To establish two simultaneous VPN connections, the VPN client is configured to create and/or use two Transmission Control Protocol (TCP) sockets. In one example, a first VPN connection can be a primary VPN connection and a second VPN connection can be a dormant VPN connection configured as a backup in case of a service interruption with the first VPN connection. In another example, a data flow can be split across the first and second VPN connections, or alternate between using the first and second VPN connections, based on performance parameters.

Creating two simultaneous VPN connections for a VPN client

The techniques described herein enable the establishment of two simultaneous virtual private network (VPN) connections between a VPN gateway and a VPN client. The system is configured to update a routing table advertised to network resources when a VPN server instance fails and/or is taken offline. When a first VPN server instance fails and/or is taken offline, the first VPN server instance releases a claim of ownership on its range of IP addresses. After this release occurs, the second VPN server instance is configured to claim ownership of the range of IP addresses that used to be owned by the first VPN server instance. This updated claim of ownership is captured in an updated routing table that can then be advertised to the network resources. Consequently, the network resources use this updated routing table to correctly determine which VPN server instance to send data intended for the VPN client.

Managing data traffic for two simultaneous VPN connections with a VPN client

Techniques for dynamically scaling instances of virtual private network (VPN) gateway in a cloud computing system are disclosed herein. In one embodiment, a method includes determining whether a number of packets processed by a first instance of the VPN gateway exceeds a preset threshold. In response to determining that the number of packets exceeds the preset threshold, a new security association (SA) corresponding to a portion of the VPN network traffic is created. Upon completion of creating the SA, a load balancing policy at a load balancer is modified to forward a portion of the network traffic to a second instance of the VPN gateway when an incoming packet contains a security parameter index (SPI) corresponding to the created SA in its EPS header.

Dynamic scaling of virtual private network connections

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Redmond, WA, United States of America

Shivakumar Thangapandi