Enabling multimedia services in unified access network

Unified access to VPNs enables considerable flexibility in the way remote locations connect to a VPN. The overall design goal of this approach requires support for all services inherent to VPNs, including multimedia ones. The classical approach to building VPNs, such as ATM or frame relay, can enable strong support for multimedia traffic because of the ability to provide strict QoS guarantees. The architectural requirement of using IP as network protocol can lead to problems in the transport of multicast streams for VPNs based on classical networks. New approaches, such as MPLS VPNs, promise even greater flexibility and scalability through the use of native means for IP packet delivery. Methods that can provide multicast traffic transport in those approaches need to be investigated. Different access technologies have different characteristics regarding the ability to deliver multimedia traffic and are investigated in terms of their usefulness for such purposes.