Enhancing Bandwidth Utilization of IP Telephony Over IPv6 Networks

The demand for the telecommunication services,such as IP telephony,has increased dramatically during the COVID-19 pandemic lockdown.IP tele-phony should be enhanced to provide the expected quality.One of the issues that should be investigated in IP telephony is bandwidth utilization.IP telephony pro-duces very small speech samples attached to a large packet header.The header of the IP telephony consumes a considerable share of the bandwidth allotted to the IP telephony.This wastes the network's bandwidth and influences the IP telephony quality.This paper proposes a mechanism(called Smallerize)that reduces the bandwidth consumed by both the speech sample and the header.This is achieved by assembling numerous IP telephony packets in one header and use the header'sfields to carry the speech sample.Several metrics have been used to measure the achievement Smallerize mechanism.The number of calls has been increased by 245.1%compared to the typical mechanism.The bandwidth saving has also reached 68%with the G.28 codec.Therefore,Smallerize is a possible mechanism to enhance bandwidth utilization of the IP telephony.

Implementation of ITU-T G.729 Speech Codec in IP Telephony Gateway

ITU-T G. 729 is the primarily recommended speech codec by H. 323 standard. This paper describes how to implement G. 729 codec in IP telephony gateway, and goes deep into the programming skills on TMS320C6201 DSP and optimizing methods of program code to reduce the speech processing delay time of G. 729 codec. Due to adopting these optimizing methods and programming skills, we have implemented a high-speed speech codec that can process concurrently 20 voice channels with single TMS320C6201 chip in IP telephony gateway. Finally, the paper analyzes the performance results of ITU-T G. 729 codec based on TMS320C6201.

A Study of the Next Generation Intelligent Networks Interworking with IP Networks

In the past three years, the author has participated in several projects involved in Intelligent Network (IN). In 1997, we started our research on the project 'The Integration of IN and B ISDN' supported by National Science Foundation. Since 1999, the author has engaged in the project 'the Next Generation IN Based Service Platform Interworking with IP Networks' supported by the National 863 Project. While working on the project, the author made a deep research on the architecture and the key technology of the next generation IN defined by ITU T IN CS3 and CS4. In the following parts. 1. I conclude the research work and the innovation in my dissertation. The early research on the interworking of IN and Internet, despite the shortage of materials, the interworking architecture by means of IAF is analyzed. Some key techniques like triggering intelligent service and reporting dynamic IP address are solved. Some new SIBs and INAPs are added, and the dial up software of users is enhanced, too. The incoming call notification service is designed. What we have done paves the way for the future research. 2. The gateway based architecture for the interworking of IN and Internet is described. Considering the research results from ITU, PINT work group and TIPHON work group, we emphasize that the interworking scenario through MG,SCG and C/BG is promising. Based on the CIN software developed by ourselves, we provide the scenario to enhance the function entities and signaling protocol. We address the function of entities and the interaction of signaling with an example like ICW service. 3. With the introduction of mobile agent technology, the author proposes the distributed IN which can be integrated with IP networks. According to the drawbacks of the centralized IN, we address the architecture and conceptual model of distributed IN to support advanced service in IP Telephony. We try to illustrate the role and relationship between function entities. We also present a smooth evolution scenario from today's networks. 4. A novel service control software based on mobile agent technology is proposed. With the adiquately understanding of CIN 02 SCP, we present the OO based framework of MA SCP. And we explore how our new SCP works. We prove that our solution can work efficiently by a service called VPN in IP Telephony. 5. The concept, architecture and related research of active networks are introduced. We take the ticket order service as an example, give the simulation results and prove that active networks can improve the performance of distributed applications. We also compare active networks with mobile agent based IN. We highlight that the two techniques can complement each other and borrow lessons from the other one. 6. The architecture of Broadband IN is discussed. From the angles of architecture, access mode and software structure, a novel B IP that can support multimedia services such as VoD and B VPN is given. Moreover, B IP is introduced into VoD service. To improve the performance of VoD, we present a novel replacement algorithm with the multi layer decision with multi factors.