![]() In the DiffServ architecture, networks differentiate the QoS per class based on suitable per hop behavior (PHB), rather than per flow as in IntServ. Yet, the scalability issues related to the IntServ model mean the DiffServ model is preferable for the development of IP QoS in core networks. ![]() The network is then able to properly fulfill the QoS requests using a clearly defined admission control framework. The QoS clients use an RSVP (Resource Reservation Protocol) to express their QoS requests to the network. The IntServ model includes the definition of a signaling mechanism and admission control framework. Two architectural models for IP QoS have already been proposed by the IETF : Integrated Services (IntServ) and Differentiated Services (DiffServ). As such, there is much interest in the Internet community on how to automate the process of resource allocation at the time of subscription, during the call setup process, or at the data transfer time. Quality of service is an essential technology that should be supported over networks. However, many problems still remain as regards providing services for multimedia applications. Session Initiation Protocol (SIP) is an important and evolving protocol, which provides text-based signaling that can be easily adapted to establish, maintain, change, and tear-down multimedia sessions between two end-points or more, and has recently received a lot of attention from the Internet Engineering Task Force (IETF), making it a promising signaling protocol for present day and future IP-based wired and wireless multimedia services. In addition, a new session establishment signaling method is needed for access control in accordance with the service level agreement (SLA) and for resource reservation to guarantee seamless QoS connections. ![]() Thus, next-generation all-IP-based networks need a new type of network structure that can support various applications requiring differentiated traffic processing and high quality of service (QoS) among end-to-end user terminals. The Internet is currently being extending from a traditional simple network for voice or message services to an integrated service network providing multimedia services, such as voice and image, video streaming, and web-applications. Simulations under various environments show appropriate parameter ranges in terms of the server capacity and number of users for the required delay bounds. Numerical analysis is then used to derive the session establishment delay for the proposed signaling scenarios. To control the network access of users and manage network resources, the use of policy servers and QoS extended SIP signaling is presented. Accordingly, this paper proposes a new QoS support SIP-based network architecture that integrates SIP clients, QoS-enabled SIP servers, and policy-based network management in a combined IntServ and DiffServ networks. In next-generation networks based on all-IP, it is expected that SIP will play an important role in session establishment between end-to-end user terminals. With the development of next-generation convergence networks, the Internet needs to support new network architecture and session management methods that can support various applications requiring differentiated traffic processing and high quality of services, instead of the conventional best-effort service.
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