Toward QoS-capable virtual private networks

Abstract

What is a virtual private network (VPN)? This paper analyzes the various definitions that exist and explains the different viewpoints that have led to their emergence. Furthermore, it describes an evolution from today's Internet‐based VPNs to emerging solutions by which quality of service (QoS) for a variety of service classes can be guaranteed. Specifically, this paper discusses two methods of implementing QoS‐capable VPNs—one defined over a pure asynchronous transfer mode (ATM) infrastructure and another based on multiprotocol label switching (MPLS), a new protocol that offers a connection‐oriented approach to Internet protocol (IP) transport over a variety of infrastructures. In the near term, it might make sense for a service provider to offer VPN services over an existing ATM infrastructure. However, in the long term, as this paper proposes, evolution toward the MPLS‐based approach is the course to follow.

Enterprise networking for the new millennium

“…Service providers implement their contracted SLAs by assigning parts of their networks to each customer's traffic. 7 This can be troublesome from two perspectives. The first is the question "Am I really getting what I need?"…”

Modeling and performance analysis for IPv6 traffic with multiple QoS classes

“…The Internet Engineering Task Force (IETF) has recommended a differentiated service mechanism for the traf®c with different QoS requirement on priority basis [17,18]. IPv6 [2] is ideally designed for supporting such differentiated services [17].…”

“…The Internet Engineering Task Force (IETF) has recommended a differentiated service mechanism for the traf®c with different QoS requirement on priority basis [17,18]. IPv6 [2] is ideally designed for supporting such differentiated services [17]. However, in current IP-based networks, when the data are encrypted, it may be dif®cult for the network to determine the class-of-service based on packet content in the network layer, especially when a multiple class of QoS is involved.…”