ATLANTA, GA -- In a move to help network managers prioritize traffic on their enterprise networks and use available bandwidth more efficiently, AT&T (NYSE: T) today announced new classes of service for its private IP Virtual Private Networks (VPNs) and its managed dedicated Internet access services. AT&T announced the services at the NetWorld + Interop tradeshow here. Effective immediately, AT&T will support three classes of service for its private IP VPNs -- high priority, low priority, and best effort. Network managers can assign these classes of service in any configuration to address the specific bandwidth demands of their network traffic. AT&T's private IP VPN offer is based on its IP-Enabled Frame Relay (IPFR) service that uses Multiprotocol Label Switching technology to implement a VPN on customers' existing frame relay networks. AT&T Managed Router Service for IPFR, which was recently announced, also will support these classes of service. Classes of service allow businesses to differentiate one application running on their network from another. The capability helps network managers use their network bandwidth more efficiently by letting them map applications into "classes," assign a priority to each class, and based upon the priority, treat the classes differently. AT&T Corp.