Internet Communication Framework 
The Internet Communication Framework enables you to use standard protocols (HTTP, HTTPS, and SMTP) to operate communications between systems through the Internet. You do not need any additional SAP program libraries (other than the SAP Web Application Server). The only condition is that your system platform is Internet-compliant. This scenario gives you a maximum amount of flexibility in responding to varying communication requirements.
Communications operated through the ICF have the following benefits:
· Increased security. The HTTPS protocol guarantees secure data transmission at the same level as modern security standards for RFC/SNC communication and other interfaces.
· Increased flexibility. Using the ICF, the user can open a connection to an SAP system across the Internet from any location.
· Reduced technological barriers. The open HTTP standard is used worldwide, which makes it efficient to install and configure.
The Internet Communication Framework enables an application to generate a response to a request. A client (such as a Web browser) sends a HTTP request to the server. The Internet Communication Framework (ICF) forwards the request to an application. The application then gathers data as a response and sends it back to the client through the ICF. The browser displays the data in the response.
The Internet Communication Framework (ICF) provides the infrastructure for handling HTTP requests in work processes in an SAP system (server and client).
If you are using the system as a server, you need a HTTP Request Handler, which you can create yourself. Defining the HTTP request handler yourself allows you to use the ICF flexibly in your application. However, HTTP request handlers are also shipped with the SAP system.
Also read the section 
Architecture of the
SAP Web AS. As well as providing helpful information about the structure
of the SAP Web Application Server, this documentation also contains
information about how the Internet Communication
Manager (ICM) works.
The
HTTP request handler for Business Server Pages (BSP) is the most commonly used
handler. You can use this handler to develop Web applications. The way BSPs
work and how you can use them is explained in Business Server
Pages.
This section deals with the ICF on a general level. It describes what HTTP request handlers are and how you create them. It also describes the client role of the ICF.
We start with an overview of the architecture, split into sections for the server side and the client side. These sections are then followed by user-oriented sections for administrators and developers.
Administration: HTTP Communication Using the SAP System
Begin by reading the Architecture Overview.