When working with MetaFrame XP server-based computing environments, the term "ICA" will come up frequently. It is important to understand the context in which it is used, because ICA (Independent Computing Architecture) is both a protocol and file type.
The ICA protocol is the network protocol used by Citrix ICA client devices and MetaFrame XP servers for client-to-server session communication. The ICA protocol actually transmits keystrokes and mouse movements from the client to the MetaFrame XP server, and screen images from the server to the client. This protocol is also responsible for the "advanced" features of MetaFrame XP, such as mapping a user's clipboard, local drives, and local ports, as well as printing and encryption.
The ICA protocol is a high-level protocol that can run on top of many standard network protocols, including TCP/IP, IPX/SPX, and NetBIOS.
ICA File Type
"ICA" is also a type of file. ICA files (with the ".ica" file extension) are text-based files that contain instructions and parameters for connecting to MetaFrame XP servers. Users with Citrix ICA client software installed on their computers can double-click an ICA file to launch the Citrix ICA client software, establishing a session (via the ICA protocol) with the MetaFrame XP server. This session is established based on the parameters contained in the ICA file. An ICA file has the "ini" file format, so it may be viewed and edited with any text editor.
It is important to note that while using ICA files allows users to connect to MetaFrame XP servers, there easier ways of accomplishing this. These other ways are covered throughout this book.