Â Â Â Â•Â Â Physical LayerÂ—Defining the electrical and mechanical interfaces to the network, it determines the upper limit of the transmission speed needed for audio and video information.
Â Â Â Â•Â Â Data Link LayerÂ—Comprising the access protocol to the physical layer, it deals with error correction, flow control, frame synchronization, and the transmission of data frames.
Â Â Â Â•Â Â Network LayerÂ—Containing switches and router packets, it establishes logical associations of remote stations and provides services such as addressing, congestion control, error handling, internetworking, and packet sequencing.
Â Â Â Â•Â Â Transport LayerÂ—Provides a program-to-program connection.
Â Â Â Â•Â Â Session LayerÂ—Coordinates interactions between user application processes on different hosts, including multi-cast (defined as one to many, multi-drop), many-to-one sessions, and point-to-point.
Â Â Â Â•Â Â Presentation LayerÂ—Manages abstract data structures and converts different data formats and codes.
Â Â Â Â Â Â Â Â•Â Â Application LayerÂ—Contains protocols such as ftp, SMTP, telnet, and email.
The TCP/IP protocol used on the Internet collapses layers 5, 6, and 7 of the above OSI Model to a single application layer, thus forming a five-layer protocol.