In differentiated services, packet classification is used to categorize incoming packets into multiple forwarding classes based on pre-defined filters and make information accessible for quality of service. Although numerous algorithms have presented novel data structures to improve the search performance of packet classification, the performance of these algorithms are usually limited by the characteristics of filter databases. In this paper, we use a different approach of filter preprocessing to enhance the search performance of packet classification. Before generating the searchable data structures, we cluster filters in a bottom-up manner. The procedure of the filter clustering merges filters with high degrees of similarity. The experimental results show that the technique of filter clustering could significantly improve the search performance of Pruned Tuple Space Search, a notable hash-based algorithm. As compared to the prominent existing algorithms, our enhanced Pruned Tuple Space Search also has superior performance in terms of speed and space.

Based on an estimation model of video subjective quality, a bandwidth reallocation strategy for video communications on NGN is presented. Experimental results show that the average PSNR of recovery video quality can be greatly increased by using the proposed method when the network bandwidth decreases.

As the network speed becomes faster and requirements about various services are increased, a number of groups are currently developing technologies aimed at evolving and enhancing the capabilities of existing network. A Next-Generation Network (NGN) is defined as a hybrid telecommunications network that employs new distributed processing techniques to provide all types of services. By integrating the Intelligent Network (IN) technology and the Mobile Agent (MA) technology we can support service flexibility and service portability in NGN. In this paper, we propose a caching-based mobile agent model for NGN and analyze the performance of this model. The mobile agent technology increases the service portability and the caching strategy does the service reusability. Each Physical Entity (PE) has MAs within their repository through the caching strategy and processes service requests from users without the control of the central system such as Service Control Point (SCP). Therefore, we can decrease the total network load and the response time for user requests.

This paper describes the JAINTM JavaTM Call Control (JCC) Application Programming Interface (API), and its relationship to network protocols, in particular the Session Initiation Protocol (SIP). JCC is a high-level object-oriented open, standard API for Next Generation Network (NGN) softswitches that enables rapid creation, by third parties, of services that can run independently of the underlying network technology (e.g. wireless, wired, packet, IP, PSTN) and protocols. SIP is a protocol that has been proposed for a wide variety of uses in IP networks, including call control. We argue that instead of being competitors, JCC and SIP are complementary, with JCC offering higher-layer programming abstractions and protocol-independence, and demonstrate by examples how to map JCC version 1.0 to a SIP environment. We thus show that for common call control applications using JCC is simpler, faster and less maintenance intensive than using SIP directly.