Dynamic VPN Optimization by ALTO Guidance

Virtual Private Networks (VPNs) are a key component of cloud computing systems, since they provide isolated connectivity between geographically separated users. The elasticity in cloud computing and new usage patterns such as cloud bursting require VPNs to be more dynamic than traditional solutions used by network service providers. Managing and optimizing the topology of VPNs requires insight into the underlying wide area network topology and benefits from new network interfaces currently discussed for Software Defined Networks (SDN). This paper presents the use of the Application-Layer Traffic Optimization (ALTO) protocol for VPN optimization. ALTO is a standardized solution for exposure of abstract topology information to a variety of applications, including cloud management systems. We demonstrate the use of ALTO in determining how to scale-out a VPN on demand. We also present a prototype of an ALTO-based dynamic VPN management, which is based on a carrier-grade network management system. Our results show that ALTO is a powerful topology abstraction approach that enables informed VPN scale-out decisions by applications.