Gurukul My Project Guide

Author: Henry Sinnreich

Summary

The Web Communications Project at the Illinois Institute of Technology aims to develop the technology and sample implementations for Web based applications that include real-time voice and video communications. We envisage Web communication widgets [3] for application developers as open source software and plan to use existing Web software, languages, data and communication standards for Web communication widgets. The project aims for Web communication widgets to become as common on Web pages as other components, such as layout, buttons, text fields, images, multimedia players and other.

Motivation

Most data based Internet applications use HTTP as the only network application protocol. Web based applications include personal communications such as email, file transfer, IM and chat, shopping, financial transactions, information, productivity and entertainment. Productivity applications include office and enterprise applications, increasingly often placed in the cloud. Web applications at present are however not suited for real-time voice, though there are no technical reasons why they could not support all the data communications required for such as voice and video signaling.

At the same time, global voice communications, both fixed and mobile use VoIP based on SIP standards for interoperability, but have not produced any significant applications other than emulating legacy telephony services. Other real-time communications, such as conferencing with video, desktop and application sharing most often use a mix of Web applications for data sharing and distinct applications and protocols for voice and video.

Presence, IM and chat are pure data applications and have been around since the emergence of the Internet using a great variety of protocols that still live in many incompatible IM and chat networks. There are really no good technical reasons for this, except the longevity of legacy and the market power of incumbents.

In essence, data based Web applications and real-time communications for voice, video and other such as games have distinct development environments and have also distinct technical orientations. As a result Web application developers most often don’t have the skills or means to develop applications that include real time communications and VoIP developers have similar constraints when developing non-voice applications.

Web based data application developers’ number in the 10s of millions.
The main objective of the IIT Web Communications Project is to enable Web application developers to add real-time communications such as voice and video, presence, chat and IM to their Web applications. Another objective is to extend the benefits of the Web architecture and software development tools to real time communication application developers.

Background

Background elements from both the Internet and telecommunications are helpful for the understanding of this project.

Internet Applications

Based on the success of key initial Internet applications: File transfer, email and the Web, the IETF embarked in the mid ‘902 on an extended standards protocol development program for other applications such as RTP for real-time media transport, SIP and SDP for discovery and session establishment, RTSP for network player applications, XMPP for IM and chat, MEGACO for so called “soft switches” and many other, such as the SIP based conference standards.
Note the proliferation of network application standards have also caused the need for complex and multiple tools for the traversal of NAT which is different for Web apps, for VoIP, for games or for RTSP based streaming media.

New communication forms have however emerged on the Web outside the world of IETF standards, such as peer-to-peer for media streaming (Bittorent) and for VoIP (Skype), as well as pure Web based applications: Wikis, blogs, web conferencing, social networks for fixed and for mobile networks alike, location based applications and mobile social media, and last but not least cloud computing.

As of this writing, the overwhelming majority of all Internet and private IP network applications use however one single network application protocol for data: HTTP.
For real-time media UDP is required with some simple, RTP-like protocol, or its functionality moved to the application, such as used by Skype where voice and video travel in UDP packets under control from the application.

This lesson of history shows in hindsight that only two Internet protocols are required for web communications: HTTP and UDP. All other application specific functionality can reside in the application itself; in the user client and/or in a Web feature server.
No other network standards are required, but application standards such as standard languages and data standards and various standards for security and intellectual property protection.

Telecommunication Services

The fixed and mobile telecommunications industry has overwhelmingly embraced IETF real-time communication standards, though in order to meet telecom business models, such standards as SIP and SDP have been significantly expanded to preserve telecom type services and business models. Examples are ITU-T and ETSI standards for fixed and mobile networks and matching 3GPP and OMA standards for mobile networks.
This has led however to VoIP network designs that contradict basic Internet architectural principles, such as end-to-end and network transparency.
It is the main difference between VoIP technology on the Internet and VoIP in closed service provider networks.

Web Communication Components
The IIT projects aims to develop sample applications using the following components:

1. SIP API for Web communications
2. SDP replacement by metadata
3. RTP-like functionality for UDP media packets
4. Web style open authentication
5. HIP for NAT traversal, mobility, IPv6 migration and multi-homing

References [2] and [3] provide a more detailed description of these components.

We believe Web applications with these components meet the following objectives:

• Make Web communications accessible to millions of web developers
• Maximize the end user experience and security
• Preserve the huge investment in and experience from SIP based VoIP by service providers, while at the same time assuring adherence to Internet and Web standards and software development tools.

References

[1] SIP APIs for Communications on the Web, Internet-Draft. Work in progress, IETF 2010.
[2] “Communications on the Web”, private draft paper
[3] SWT: The Standards Widgets Tool, http://www.eclipse.org/swt/