When an Internet user requests an ITS service by clicking on a URL hyperlink or keying in a URL address in a Web browser to run a IACEWT, the request is processed as follows: 

1. The Web browser passes the request to the Web server.

2. The Web server calls the server-specific ITS extension WGate - WGate is the link between the ITS and the Web server. WGate is a Web server extension that encapsulates the various supported HTTP server interfaces such as: CGI (Common Gateway Interface), NSAPI (Netscape Server Application Programming Interface), ISAPI (Internet Server Application Programming Interface) in a transparent manner that passes the requested data to the ITS AGate component.

3. WGate forwards the request to the ITS server process called AGate (which may or may not reside on the same machine.)

4. AGate is the link between the ITS and the SAP R3 application server. AGate is the core processing component of the ITS. It receives Web browser request from WGate and communicates with the SAP R3 application server via the DIAG or RFC protocol.

5. AGate then processes the requests, and sends all relevant details (including logon information) to the SAP R3 system, which either starts the first dialog step of a new transaction of submits further data for the next dialog step of a transaction already started. 

6. SAP R3 starts the transaction for the service requested and sends the screen output to AGate. 

7. When the dialog step has finished, AGate retrieves the result from SAP R3, and is responsible for session management, including mapping of SAP R3 screen or function modules to HTML, web session timeout handling, SAP R3 connection management and generation of HTML documents that are sent back to the Web browser client.

8. AGate forwards the formatted HTML page to WGate. 

9. WGate forwards the formatted HTML page to the Web server.

10. The Web server sends the formatted HTML page to the Web browser, where it can be viewed by the user.

There are three restrictions to this approach:

1. The SAP R3 release must be at least version 3.1I or higher.

2. You can only use those Internet Application Components that were shipped with the SAP R3 release you are using.

3. ITS 6.10 should only be installed in front of an SAP E3 kernel release 6.10 (e.g. CRM 3.0) 

>>Wgate
Microsoft NT 4.0 Server
Microsoft Web Server (ISAPI)
Netscape Web Server (NASPI) 
Apache HTTP Server (Apache Module)
Any CGI Web Server (CGI) 
Microsoft windows 2000 Server
Microsoft Web Server (ISAPI)
Linux/Intel
Apache HTTP Server (Apache Module) 

>>Agate
Microsoft NT4.0 Server
Microsoft Windows 2000 Server
SAP@Web Studio 
Microsoft NT 4.0 Workstation
Microsoft Windows 2000 Workstation 

*** ITS 6.10 Server Platforms ***

>>Wgate
Microsoft NT 4.0 Server
Microsoft Web Server (ISAPI)
Netscape Web Server (NASPI)
Apache HTTP Server (Apache Module)
Any CGI Web Server (CGI)
Microsoft windows 2000 Server
Microsoft Web Server (ISAPI)
Microsoft XP Server
Linux/Intel
Apache HTTP Server (Apache Module)

>>Agate
Microsoft NT4.0 Server
Microsoft Windows 2000 Server
Microsoft XP Server 
SAP@Web Studio 
Microsoft NT 4.0 Workstation
Microsoft Windows 2000 Workstation 
Microsoft XP Server

Fast Links:
Daily Admin Task
SAP Administrator Daily Activities

SAP Basis Admin Books
SAP System Administration, Security, Authorization, ALE, Performance Tuning Reference Books

SAP Basis Tips
SAP BC Tips and Basis Components

Administration In SAP - Sapgui, Unix, SAP ITS, Router, Client Copy and IDES 

Best regards,
SAP Basis, ABAP Programming and Other IMG Stuff
http://www.erpgreat.com