Siemens Enterprise Use Equinox to Power "Communication as a Service"

Siemens Enterprise Communications have been developing telephony switches for the past 100 years, moving to software focussed solutions in the last decade. To bring their technology offerings up to date, Eclipse Equinox was chosen to give them a solid foundation for their OpenScape Unified Communications suite. Over the last three years, Siemens have proven the success of this approach with more than 200 installations serving over 40,000 users.

Moving From The Switch To The Server

Siemen's main application is called OpenScape Unified Communications (UC) and is at the heart of Siemens Enterprises unified communications portfolio. The OpenScape UC Server is an innovative software foundation that revolutionizes business communications by removing the barriers between voice, video and data.

The server enables presence, administration, session control and other shared services across the entire OpenScape UC suite of applications. This suite incorporates enterprise grade voice services with carrier grade scalability and reliability, IP least-cost routing, video conferencing, mobility, unified messaging, and role-based UC applications.

The UC server is based on the Siemens OpenSOA,which consists of a number of services all built on top of Equinox. The services provide core functionality like database access, licensing, security or administration as well as domain specific services like routing, reporting and presence.

Figure 1: Architectural Overview of an OpenScape Unified Communications installation

At it's most basic level, OpenScape Unified Communications replaces traditional PBX systems used in corporations all across the world. While traditional telephony switches have scalability issues for large installations, with a maximum capacity of 50,000 users, Siemens software solution scales up to twice that size, with 100,000 clients.

The application suite is built to scale from small and medium sized businesses to large enterprises, addressing the problems of employee overload and latency as well as needless communication costs. It saves employee time by combining calls, conferencing, fax and messaging into a one single portal - with features such as conference calling, presence, call routing and mobility.

The system is an interesting mix of technologies across three tiers. The UC server, mentioned above is at the core, providing all the services to the client side and interacting with the IP-based telephony switch. With the services being provided and run on the server side, clients can use a choice of lightweight applications to run these services. The standard desktop client is written in Microsoft .NET, and allows the user to take advantage of all aspects of the OpenScape suite such as voice, video conferencing, instant messaging and real-time collaboration. The application even allows you to use your desktop as a software based phone. A set of services are also available to the user through a browser based application, again written in .NET. Users on the move can also access some of the services from their mobile device.

All the heavy processing is done on the server side, with Equinox providing these services to any client side application, regardless of it's implementation. By providing these services through a web service API, customers have the option to integrate OpenScape functionality into their existing applications.

Using Equinox As the Foundation

With OpenSOA, Siemens have adopted a service oriented architecture approach to make the communication capabilities that are required across all applications, whether provided by Siemens or integrated into custom applications.

Figure 2: This graphic indicates that the Core and Shared Services of OpenSOA enable Siemens application offerings for Unified Messaging, Unified Communications and Contact Center. The reach of OpenSOA will also be extended by a new SDK-based OpenSOA Developer's Ecosystem, to enable new composite applications supporting consistent access by diverse clients and devices.

OpenSOA forms a stable foundation for all communications applications. While one approach to SOA is to reuse existing legacy applications with a Web services interface, Siemens have refactored all common services and business functionality using OSGi bundles. This allows Siemens to fulfil their vision of delivering software-based 'Communications as a Service' and to tie bundles for building new applications. This service oriented, OSGi approach gives the following benefits to Siemens:

Easier integration through open standards and greater application portability
More unified, flexible client and administrative interfaces
Common functionality synergized across applications
Business process workflow orientation
Faster, more flexible software delivery

With OSGi at the core of Siemens software strategy, Equinox was chosen as the implementation, following initial prototypes with Knopflerfish. As Equinox became the reference implementation for the technology, it made most sense to move, especially as the team had noticed that the Equinox community was one of the most active development communities. All application logic is written on top of Equinox, with Apache Tomcat as the web server serving thin clients as well as for the management portal. Equinox was a lighter and faster alternative to heavyweight J2EE server. By adding in an implementation of RFC119 for distributed OSGi, the bundles can communicate across multiple servers, providing further scalability advantages to the Equinox implementation. While it is possible to run Equinox on the client side, Siemens have taken the approach of thin clients on the desktop. Right now, the team of 250 developers are using the 3.5 implementation of Equinox to provide their OSGi bundles.

Eclipse For The Future

Since adopting Eclipse-based technologies? Siemens have found that the Eclipse community is among the most helpful, providing detailed answers to any questions that arose while finding their feet with OSGi and Equinox. In return, once they themselves gained an in-depth knowledge of Equinox, the Siemens team were able to give back to the community, and continue to benefit from the collective knowledge of their peers in the community to provide even better solutions.

With Eclipse technologies being used throughout their architecture, Siemens foresee infinite possibilities from the eco-system. p2 is likely to be used to provision the bundles, rather than the current proprietary mechanism for the application distribution. EclipseLink, as the reference implementation for the Java Persistance API, will replace the current OpenJPA implementation. BIRT has proven to be a compelling choice for high quality reporting and can form the base for future contact center reporting, while the relationship with ECF continues. When the Virgo project is accepted, the team is eager to take advantage of the extensions that will be available, replacing the current system management infrastructure. The web server itself could be due for a refactor, taking out Tomcat and replacing it with Jetty. With the depth of technologies available and growing within the Eclipse eco-system, Siemens are happy to have taken the first steps into Eclipse adoption with their move to Equinox.