On the development of Voice over IP

This record of study documents the experience acquired during my internship at Sonus Networks, Inc. for the Doctor of Engineering Program. In this record of study, I have surveyed and analyzed the current standardization status of Voice over Internet Protocol (VoIP) security and proposed an Internet draft on secure retargeting and response identity. The draft provides a simple and comprehensive solution to the response identity, call recipient identity and intermediate server retargeting problems in the Session Initiation Protocol (SIP) call setup process. To support product line development and enable product evolution in the quickly growing VoIP market, I have proposed a generic development framework for SIP application servers. The common and open architecture of the framework supports multiple products development and facilitates integration of new service modules. The systematical reuse of proven software design and implementation enables companies to reduce the development cost and shorten the time-to-market. As the development and diffusion of VoIP can never be isolated from the social sphere, I have investigated the current status, influence and interaction of three most important factors: standardization, market forces and government regulation on the development and diffusion of VoIP. The worldwide deregulation and market privatization have caused the transition of the standards development model. This transition in turn influences the market diffusion. Other than standardization, market forces including customer needs, the revenue pressure on carriers and vendors, competitive and economic environment, social culture and regulation uncertainties create both threats and opportunities. I have examined market drivers and obstacles in the current VoIP adoption stage, analyzed current VoIP market players and their strategies, and predicted the direction of VoIP business. The regulation creates the macro environment in which VoIP develops and diffuses. I have explored modern telecommunications regulation principles based on which government makes decisions on most current issues, including 911 support, mergers and acquisitions, interconnection obligation and leasing rights, rate structure and universal service fees

A distributed intelligent network based on CORBA and SCTP

The telecommunications services marketplace is undergoing radical change due to the rapid convergence and evolution of telecommunications and computing technologies. Traditionally telecommunications service providers’ ability to deliver network services has been through Intelligent Network (IN) platforms. The IN may be characterised as envisioning centralised processing of distributed service requests from a limited number of quasi-proprietary nodes with inflexible connections to the network management system and third party networks. The nodes are inter-linked by the operator’s highly reliable but expensive SS.7 network. To leverage this technology as the core of new multi-media services several key technical challenges must be overcome. These include: integration of the IN with new technologies for service delivery, enhanced integration with network management services, enabling third party service providers and reducing operating costs by using more general-purpose computing and networking equipment. In this thesis we present a general architecture that defines the framework and techniques required to realise an open, flexible, middleware (CORBA)-based distributed intelligent network (DIN). This extensible architecture naturally encapsulates the full range of traditional service network technologies, for example IN (fixed network), GSM-MAP and CAMEL. Fundamental to this architecture are mechanisms for inter-working with the existing IN infrastructure, to enable gradual migration within a domain and inter-working between IN and DIN domains. The DIN architecture compliments current research on third party service provision, service management and integration Internet-based servers. Given the dependence of such a distributed service platform on the transport network that links computational nodes, this thesis also includes a detailed study of the emergent IP-based telecommunications transport protocol of choice, Stream Control Transmission Protocol (SCTP). In order to comply with the rigorous performance constraints of this domain, prototyping, simulation and analytic modelling of the DIN based on SCTP have been carried out. This includes the first detailed analysis of the operation of SCTP congestion controls under a variety of network conditions leading to a number of suggested improvements in the operation of the protocol. Finally we describe a new analytic framework for dimensioning networks with competing multi-homed SCTP flows in a DIN. This framework can be used for any multi-homed SCTP network e.g. one transporting SIP or HTTP

SIPBIO : biometrics SIP extension

During the last few decades biometric technologies have become an important research field in computer security. Their deployment, however, in heterogeneous enterprise systems, is complex due to the lack of standardisation. Session Initiation Protocol (SIP) is a popular communication protocol widely used in voice over Internet protocol networks; due to its flexibility, SIP has been broadly adopted in telecommunications for carrier level and telephony systems. This thesis proposes the use of SIPBIO, an extension to SIP, to establish and control multimedia sessions for biometric interactions. For biometric usage in telecommunications networks, a synthesis of techniques to use human characteristics as challenge tokens for access to network resources is first presented. An overview of the SIP protocol is then exposed, by focusing on understanding SIP messages and their component elements. Posteriorly, advanced concepts, such as extensions to the default protocol are introduced. After the technology background review, the core of the proposal is presented with extensive use-case scenarios of biometric operations and the introduction of necessary SIPBIO requirements. Formal processes are defined along with the method to extend SIP to the proposed SIPBIO protocol. It follows a detailed outline of all headers and body components that give form to SIPBIO and define its nature. These stages provide the fundamentals for the protocol implementation. Finally, simulations of some common cases are presented to show the feasibility of SIPBIO. This can be used as a sample flow for full implementations and applications. This thesis corroborates the viability of using a SIP-based protocol for establishing, maintaining and tearing down biometric multimedia sessions

Internet Telephony : optimizing protocols, packet recovery, and packet size

Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1999.Includes bibliographical references (leaves 104-106).by Grant Ho.M.Eng

2020-2021

Contains information on courses and class descriptions as well as campus resources at Collin College.https://digitalcommons.collin.edu/catalogs/1032/thumbnail.jp

2013-2014

Contains information on courses and class descriptions as well as campus resources at Collin College.https://digitalcommons.collin.edu/catalogs/1025/thumbnail.jp

2011-2012

Contains information on courses and class descriptions as well as campus resources at Collin College.https://digitalcommons.collin.edu/catalogs/1023/thumbnail.jp

2012-2013

Contains information on courses and class descriptions as well as campus resources at Collin College.https://digitalcommons.collin.edu/catalogs/1024/thumbnail.jp