A QoS specification proposal for IP virtual private networks

Demand for virtual private networks (VPN) are on the increase as enterprises opt for secure cost effective data networking solutions with specific quality of service (QoS) guarantees. The advantages of the Internet Protocol (IP) have made it the primary network layer protocol of choice for the future as well. Nevertheless, the concept of service differentiation and how to specify and guarantee it in IP VPN are rather difficult and often fuzzy. We propose a class of service (CoS) classification with an associated QoS parameter set for IP virtual private networks in the wide area. We study various scenarios and, in each case, we derive the conditions under which appropriate QoS can be guaranteed for each CoS by policing the aggregate arrival rates of each class from each VPN access interface into the IP network, thereby eliminating the difficulties associated with accurately estimating the end-to-end traffic profiles. In addition to simplifying the specifications, our proposal enables the users to exploit fully the potential of service differentiation in connectionless networks.