VPN DESIGNER: A tool for design of multiservice virtual private networks

Abstract

VPN DESIGNER is a software tool for the design of intranets or virtual private networks (VPNs) on a service provider's infrastructure. The design allocates bandwidth on each link of the infrastructure to the VPNs such that, when the traffic of a customer is optimally routed over its VPN, a weighted aggregate measure of carried bandwidth over the service provider's infrastructure is maximized. Thus, this is a joint resource allocation and traffic routing problem. The traffic modeling is at the flow or call level, and the network is modeled as a multirate loss network, with effective bandwidth encapsulating all packet-level behavior. Scalability of the design process - that is, the ability to handle OC3 and higher rates - is an important contribution, and this is achieved by the systematic use of asymptotic techniques. VPN DESIGNER is written in C++ and runs on any UNIX' platform. We report on numerical results for a network having 8 nodes, 24 OC3 links, 6 services, up to 640 routes, and 8 VPNs.