Emerging ATM-based virtual private network (VPN) services offer customers a flexible way to interconnect customer premises networks (CPNs) via high-speed links. Compared with traditional leased lines, these services allow for rapid provisioning of VPN bandwidth through cooperative control between customer and provider. Customers can dynamically renegotiate the VPN bandwidth according to their current needs, paying only for the resources they actually use. In order to meet the various requirements and demands of different classes of VPN customers, a VPN provider must provide customers with the flexibility to choose their own control schemes and objectives. The focus of this paper is on enhancing the customer's capability of controlling a VPN. First, we propose a new scheme for a broadband VPN service, which is based on the virtual path group (VPG) concept. In our scheme, the customer performs VP control operations without interacting with the VPN provider, thus enabling the following merits: (1) the customer can share bandwidth among VPs that traverse the same physical network link in the provider's domain, thus using the VPN bandwidth more efficiently; (2) customers can perform VP control operations according to their own requirements and control objectives. Second, we outline an architecture for a customer-operated control system, which utilizes a VPG-based VPN service. The system is structured into three layers of control, which execute on different time scales. The functionalities of these layers are call processing, VP control, and VPN control, respectively. Finally, we evaluate the effectiveness of the control system, with respect to VP control.
['Mun Choon Chan', 'Hisaya Hadama', 'Rolf Stadler']
An architecture for broadband virtual networks under customer control