The Infrastructure
The combination of the CSF and SIP A/S platforms on top of IMS service networks provides a comprehensive environment that allows you to create services, host applications and services and manage the infrastructure.

Avaya's SIP A/S Gateway for CSF provides a convergence point and orchestration infrastructure that leverages the real-time services hosted within the SIP A/S platform to the CSF. We'll talk more later about CSF and how this infrastructure can be used to easily build more sophisticated converged applications.

You can use SIP Servlets.NET to manipulate SIP messages in .NET to create sophisticated applications within the SIP Servlet container. You now can use SIP Objects.NET to incorporate telephony services into your .NET applications without having to understand the nature and structure of SIP messages. Like we said, the protocol used when communicating with the SIP A/S is Simple Object Access Protocol (SOAP), and the API is based on Parlay X, a telecom standard that defines what services should be exposed and how.

SIP A/S Gateway for Connected Services Framework allows you to use the OWS services within the CSF environment to easily mashup and host applications. You do not need to understand the functionality and structure of SIP messages.

SIP Objects.NET and the SIP A/S
With SIP Objects.NET the telephony features can be consumed in one of three ways. First you can do it completely through your source code. For example, you can create a new Call object by hand in the code editor window, invoke methods on it or register event handlers. Next, you can use the components within Microsoft Visual Studio and use the basic drag and drop of pre-built components onto the design surface. Lastly, you can use the SIP Objects.NET with Microsoft's Windows Workflow Foundation (WF) since SIP Objects.NET is bundled with a rich set of WF activities. You can simply compose a workflow using drag and drop of these activities to model a workflow—without having to write any code.

Using SIP Objects.NET in Visual Studio easily allows your application to run in a Microsoft environment and trigger communications activity. After compiling and running the code, it uses OWS to interact with the SIP A/S. SIP A/S handles call set up and sends status back to SIP Objects .NET. SIP Objects.NET is bundled within the application and makes the call to SIP A/S.

Mashups and CSF
Microsoft for some time has been looking at the telephony space to provide capabilities for communities to write and share applications. CSF provides a very distributed application sharing infrastructure with many capabilities, or services within the network. This allows you as developers to use those services and build up or rather mashup complex overall applications.

For example, you can deploy a conferencing capability on the CSF and everyone using CSF has access to it and can add it to their application. You should be able to "mash" together capabilities to create bigger and better converged applications.

The CSF architecture is focused on requirements of telephony operators and the need for high availability and scalability. It is an infrastructure for developers to use to create components that mash together for more sophisticated IP telephony applications. Avaya works with Microsoft to provide APIs to interact with SIP A/S, and the capabilities therein, through the SIP A/S Gateway for CSF, which provides interaction with CSF.

Conclusion
The telephony IMS infrastructure combined with SIP A/S, OWS, SIP Objects.NET, SIP Servlets.NET and SIP A/S Gateway for CSF bring .NET developers and telephony carriers closer together in a cohesive creation and execution environment. You as a .NET developer don't even need to leave the .NET development environment to create and test applications with telephony functionality. Further, telecom carriers now have a resource for incorporating enterprise applications with their IMS-based infrastructure.