 which a receiver initiates the reservation request along a path to the source. RSVP is traditionally associated with InterServ and with a per-flow traffic handling mechanism. Due to scalability concerns over the per-flow nature of RSVP, a new QoS protocol - DiffServ - was developed. DiffServ uses the TOS (type of service) field in the IP header to sort packets into classes. For example, one TOS bit may indicate the delay requirements of the packet, and another might indicate the drop precedence. These classes are then treated accordingly during routing. No signaling on a per flow basis is required. Using DiffServ, carriers can define various grades of service such as Chapter 8 - Next-Generation OSS premium, assured and best-effort and aggregate traffic into these levels. Using these IP QoS mechanisms, carriers can create service classes such as voice IP-VPN, data IP-VPN, internet only, real-time premium video, etc. and bill for these services differently. 1.5 The Converged Network There are three main network domains that exist today - the telecommunications network comprising of the PSTN and the data backbone, the Internet which is largely a global IP-based network and the enterprise network - private local-area and wire-area networks based on mostly IP and some ATM and FR. These three separate network domains are converging as telecommunication service providers seek to add new services to their offering. Services and offerings such as long-distance VoIP, tandem-switch bypass, softswitch-based local, line sharing, DSL-based integrated voice and data and IP-VPNs will span across all these three network domains. Provisioning integrated voice and data over DSL today may require provisioning of local loop, voice gateway and Class 5 switches on one hand, and IP addresses, e-mail server and DNS on the other. Provisioning IP-VPNs require provisioning of edge and core routers as well as customer premise equipment and firewalls. The convergence of these networks means that the separate OSSs managing these silos have to