What is SIP Servlet Engine?

IP telephony service with VoIP^*1 which is a killer application of broadband services is getting more and more popular. Telecommunication carriers and service providers are beginning to look for new ways of building next-generation service environments which provide real-time communication, Internet appliances, and so on at the approach of ubiquitous computing society.

Such next-generation service environments, which will be realized by flexible integration of information (Internet/Web environments) and communication (telecommunication environments), are being created as new environments which use SIP (one of the internet protocols). SIP has high affinity with Internet/Web environments and VoIP environments.

However, to build application services (referred to as AP services), an AP platform equipped with an Application Programming Interface (referred to as API) is needed, because SIP is just a protocol for establishing a communication session between two parties. A typical AP platform in Internet/Web environments is a Web-AP server based on HTTP/Java language (for example, Tomcat, WebLogic), which is widely used as a platform for building Web-APs. For the meantime, there is no prevailing AP platform in VoIP/SIP environments because this protocol standardized in the immediate past.

OKI has developed an SIP-AP server environment which makes it possible to build and run real-time communication services based on SIP, and commercialized CenterStageAS (Application Server). CenterStageAS is a next-generation AP platform for building information-communication converged services by integrating this SIP-AP server environment and Web-AP server environments.

This document describes the architecture and technical features of CenterStageAS which aims to deliver an information-communication converged world realized by Web-SIP integration, and introduces several examples of Web-SIP converged AP services.

Aim of CenterStageAS

CenterStageAS is an AP platform based on SIP and Java used to flexibly integrate Web-AP services and VoIP-AP services. This product is not a traditional AP server for Internet/Web environments. CenterStageAS has been developed based on new concept that means to build information-communication converged services (which integrate VoIP and Web) by relating SIP-AP server environments to Web-AP server environments.

By using the powerful APIs provided with CenterStageAS, engineers who have developed mainly information software can deliver VoIP-Web converged APs with the multimedia communication functions in a short time without regard to APs for communication. For example, an engineer who has never developed VoIP-APs (such as Click to Dial) can easily provide an information-communication converged service with the telephony function in a Web screen. And engineers who have developed mainly communication software can also deliver VoIP-Web converged APs in a short time.

OKI plans to create a new market at the approach of next-generation broadband-ubiquitous society by providing the new-type service "Web communication service" through CenterStageAS.

Realizing an "SIP-Web Converged World"

CenterStageAS can seamlessly integrate information services and communication services by providing the following two development environments. Service providers can create and provide value-added information-communication converged services and service users can make efficient use of their legacy resource in their communication environment.

The open Web communication platform environment based on the industry-standard SIP/SIP Servlet.
The environment which provides easy SIP use from Web environments and easy Web use from SIP environments (The basic components for building APs which provide frameworks to integrate Web and SIP)

These development environments enhance openness of AP service development and improve convergence approach from Web environments to VoIP environments. For example, service providers can easily build Web-VoIP converged AP services shown below.

Integrating E-Commerce and Web Communication

This service can provide product information in real time in various ways including voice and chat for users who do their Web shopping.

This Web-VoIP converged environment realizes a real-time communication environment between the service provider and the users, which can improve probability of purchasing. And the service provider can transmit various information using sounds and images to the users by combining pull-type information provision which is a feature of Web and push-type information provision which is a feature of SIP, which can drive the users to buy.

In addition, providing product information timely by building the monitoring service of location and inventory data (which can be delivered as the SIP presence function) can give a sense of stability to the users.

Integrating Information Sharing and Web Communication

Integrating a corporate information portal used to share and transmit business information and various Web communication environments, such as IP telephony, ad hoc meeting, and chat can enhance the efficient operation of intra-corporate and inter-corporate business projects. For example, project members across multiple companies can hold a meeting concurrently while watching live-action footage of a shop floor through a camera-equipped PDA. This enables these members to recognize the correct situation of the shop floor and give on-target instructions when a problem occurs.

Architecture and Technical Features of CenterStageAS

Figure 4 shows the architecture of the AP platform provided by CenterStageAS. CenterStageAS, which provides an SIP server environment (proxy server/location server/load balancer) and two AP development environments (SIP Servlet API(1), Basic components(2)), builds the Web-VoIP converged AP platform which works with Web-AP server environments. The following sections describe the main technical features.

APIs for Developing Web-VoIP Converged AP Services

API-(1)

The industry-standard API (SIP Servlet API), which makes it easy to develop SIP-based VoIP-APs and integrate these VoIP-APs and Java-based Web-APs. This API supports third party application development and reusing because it is based on the standard API.

API-(2)

The basic components (the software for building APs), which makes it easier to build Web-VoIP converged AP services. Examples of the basic components are shown below.

Presence Management Component: The component used to exchange presence information set by SIP clients via SIMPLE^*2 protocol.

3PCC Management Component: The component used to do 3PCC^*3. It is used in Click to Dial etc.

Basic Communicative Functions

CenterStageAS provides the basic communicative functions, such as two-way communication and unconditional transport.

Presence Service Function

CenterStageAS provides the SIMPLE-compliant presence server function used to deliver various presence services.

Telecommunication Carrier-Level High Reliability

Its SIP server environment consists of load balancer(s) which provide the load sharing function, proxy server(s) which handle SIP based calling processes, and location server(s) which manage user information. CenterStageAS can provide high availability and reliability (which enable to continue operation without interruption) by duplicating each server function and setting multiple proxy servers.

Communication via SOAP

Even when Web-AP server environments and SIP-AP server environments are located separately on different network environments, CenterStageAS can deliver Web-VoIP converged AP services by using SOAP^*4 based communication.

CenterStageAS Package Examples

This section introduces the basic corporate communication AP package and the applied package integrated with EAI^*5.

Corporate Communication AP Package Example (Figure 5)

This package provides the environment where the registered members can communicate after understanding other members' situation by using the buddy list (presence) which displays real-time situation of the members. The packaged AP services, such as IP telephony, video telephony and meeting, and chat, bring real-time correct communication between two remote users, which can enhance the efficient operation of business.

EAI & Communication Package Example

This package is an AP package which is based on the communication package and works with an EAI tool. It provides the innovative environment which integrates business process and communication processes by relating the Web communication services to the main system built by the EAI tool. Even if a user does not know contact information of his communication partner in business process, this system can identify the most appropriate partner and connect to him using the most appropriate communication mean. This provides significant operational efficiency improvement and a new service environment which changes traditional business style.

Plans and Prospects for the Future

These information-communication converged services will be getting more and more popular in the future with advance in computing technology, such as improvement of infrastructure and progress of Web services. OKI is first providing real-time communication environments for telecommunication carriers/ISPs and then will improve capabilities of our platform to realize new Web communication environments for large-scale companies, which integrates information system and real-time communication. OKI plans to expand domain of CenterStageAS applicability. In particular, OKI aims to realize services for Internet appliances which integrate household electrical appliances, Web environments, and communication environments.

*1: Voice over IP
*2: SIP for Instant Messaging and Presence Leveraging Extensions
*3: Third Party Call Control
*4: Simple Object Access Protocol
*5: Enterprise Application Integration

Last Modified:Thu Mar 25 20:59:13 JST 2004