table of contents

Introduction

In July 2001, the Indiana Higher Education Telecommunication System (IHETS) Integrated Technologies Committee (ITC) formed an IP Video Task Force (IPVTF) to evaluate two-way interactive video over IP networks using the H.323 protocol and to recommend to the Indiana Telecommunications Network (ITN) various hardware/software and policy components required for implementing H.323 IP video.

This report will help network designers, technical coordinators, faculty, students, and administrators understand the basic functioning of H.323-based video conferencing. The section dealing with codecs should provide schools, libraries, and other institutions with guidance on the purchase of equipment.

Task Force recommendations will provide direction for ITN to implement a state-of-the-art H.323 video conferencing environment that is robust and scalable for the state of Indiana.

The topics reviewed and discussed by the IPVTF include:

• H.323 Codecs (endpoint terminal equipment)
• Multipoint Conference Units (MCU)
• Gatekeepers
• Gateways
• Dial Plan Development
• Directory Services
• Quality of Service (QoS)

The H.323 standard covers four fundamental hardware elements of a complete network system: terminals (also called codecs), gatekeepers, gateways, and MCUs. Figure 1 presents a sample implementation of these four elements, demonstrating how the IP technology will interface with existing ISDN and ATM technology. Dial plans and directory services are policy and support mechanisms used to make an H.323 network easier to use. Finally, QoS is a function of the underlying IP network, transparent to the end-user while it is working but immediately evident if it fails.

Many education institutions are already using IP-based video conferencing. Indiana University, Purdue University, and Ball State University are delivering instruction via IP video conferencing, while libraries and K-12 institutions are using the technology for administrative video conferencing. It is therefore important that ITN provide a consistent service across the shared network resource soon to avoid later having to work around multiple competing investments in equipment and policy components.

Because this technology is rapidly evolving and changing, the actual implementation of IP video on ITN will undoubtedly evolve along with the technology. Sections of this document should, however, continue to be useful reference tools for ITN customers and others considering investments in IP video.