This article gives an overview of the most promising technologies for service providers to offer virtual private network services. The focus of this article is on the analysis of the scalability implications of these virtual private network mechanisms on existing service provider backbone networks. Very often, when deploying VPN services, service providers will be confronted with a trade-off be...

The VPN Tree Routing Conjecture is a conjecture about the Virtual Private Network Design problem. It states that the symmetric version of the problem always has an optimum solution which has a tree-like structure. In recent work, Hurkens, Keijsper and Stougie (Proc. IPCO XI, 2005; SIAM J. Discrete Math., 2007) have shown that the conjecture holds when the network is a ring. A shorter proof of t...

We present an architecture for customer management and control of a broadband VPN service. The architecture is aimed at giving the VPN customer a high level of control over the traffic on the VPN, such that end-to-end requirements for the customer’s enterprise network can be met. We describe how different control and management objectives can be achieved with this architecture. Its design inclu...

The paper presents the way to provide the security to one of the recent development in computing, cloud computing. The main interest is to investigate the impact of using Virtual Private Network VPN together with firewall on cloud computing performance. Therefore, computer modeling and simulation of cloud computing with OPNET modular simulator has been conducted for the cases of cloud computing...

This paper discusses research into the capacity dimensioning of Virtual Private Network (VPN) access links for elastic traffic, such as the Web or ftp. Assuming that the coreVPN network is provisioned with a sufficiently large capacity, managing the capacity of the VPN access link comes to sharing the bandwidth for the elastic traffic of the two bottlenecks, the ingress and egress access links....

In this paper, we propose and implementVirtual Network Service (VNS), a value-added network service for deploying virtual private networks (VPN) in a managed wide area IP network. The key feature of VNS is its capability of providing a customer with a VPN that is customizable with management capabilities and performance properties comparable to a dedicated physical network. In addition, VNS ens...

Multiprotocol BGP (MP-BGP) specifies that the set of network-layer protocols to which the address carried in the Next Hop field may belong is determined by the Address Family Identifier (AFI) and the Subsequent Address Family Identifier (SAFI). The current AFI/SAFI definitions for the IPv4 address family only have provisions for advertising a Next Hop address that belongs to the IPv4 protocol w...

With IPSec/VPN policies being widely deployed, how to correctly specify and configure them is critical in enforcing security requirements. Under current practice, IPSec/VPN policies are usually specified manually by system administrators and thus prone to errors. However, dynamic aspects in the network may interfere with the existing policy set up and thus cause unexpected conflict. To deal wit...