Computer Networks

UUCP (Unix to Unix Copy) is a suite of computer programs and protocols used for communication between computer systems, originally developed for the Unix operating system.

The Internet Protocol (IP) is the primary network layer protocol in the Internet protocol suite, commonly referred to as TCP/IP.

ISP stands for Internet Service Provider, which is a company that provides individuals and organizations access to the internet.

Data transmitted over the internet is broken down into smaller, manageable units to ensure efficient routing and error checking. These units are universally known as packets.

TCP/IP stands for Transmission Control Protocol/Internet Protocol, which is the foundational suite of protocols for the internet.

TCP/IP is the fundamental communication language or protocol suite that allows computers to exchange information across the internet.

In the OSI model, the physical layer is responsible for the transmission and reception of unstructured raw bit streams over a physical medium. Therefore, the unit exchanged is a bit.

In the context of the OSI model, PPDU stands for Presentation Protocol Data Unit, which is the data unit used at the presentation layer.

The network layer is responsible for routing data, and the data unit it handles is called a packet. Bits are physical layer, frames are data link layer, and TPDU is transport layer.

The data link layer organizes data into frames for transmission across the physical medium. It handles framing, error control, and flow control at the link level.

The transport layer uses Transport Protocol Data Units (TPDU) to manage end to end communication. Other options refer to higher layer PDUs.

The application layer uses Application Protocol Data Units (APDU) to exchange information. This is the highest layer in the OSI model.

The communication subnet consists of the physical, data link, and network layers. Therefore, it lies below the transport layer, which handles end to end communication.

The physical layer is the lowest layer of the OSI model and is responsible for the transmission and reception of raw bit streams over a physical medium.

SPDU stands for Session Protocol Data Unit. It is the unit of data exchanged between session layer entities.