Internet Protocol Suite

References

• Internet Protocol Suite Wikipedia Article

Notes

The Internet protocol suite, commonly known as TCP/IP, is a framework for organizing the set of communication protocols used in the Internet and similar computer networks according to functional criteria. The foundational protocols in the suite are the Transmission Control Protocol (TCP), the User Datagram Protocol (UDP), and the Internet Protocol (IP). Early versions of the networking model were known as the Department of Defense (DoD) model because the research and development were funded by the United States Department of Defense through DARPA.

The Internet Protocol Suite provides end-to-end data communication specifying how data should be packetized, addressed, transmitted, routed, and received. The functionality is organized into four abstraction layers, which classify all related protocols according to each protocol's scope of networking. An implementation of the layers for a particular application forms a protocol stack.

Layers:

• Link Layer: contains communication methods for data that remains within a single network segment
• • The protocols of the l=ink layer operate within the scope of the local network connection to which a host is attached. This regime is called the link in TCP/IP parlance and is the lowest component layer of the suite. The link layer is used to move packets between the internet layer interfaces of two different hosts on the same link.
• Internet Layer: provides internetworking between independent networks
• • Internetworking requires sending data form the source network to the destination network. This process is called routing and is supported by host addressing and identification using the hierarchical IP addressing system. The internet layer does not distinguish between the various transport layer protocols. The Internet Protocol is the principal component of the internet layer, and it defines two addressing systems to identify network hosts and to locate them on the network.
• Transport Layer: handling host-to-host communication
• • The transport layer establishes basic data channels that applications use for task-specific data exchange.
• Application Layer: Provides process-to-process data exchange for applications
• • The application layer includes the protocols used by most applications for providing user services or exchanging application data over the network connections established by the lower-level protocols.

The Internet protocol suite has its roots in research and development sponsored by the Defense Advanced Research Projects Agency.

The end-to-end principle is a design principle in computer networking that requires application-specific features to be implemented in the communicating end nodes of the network, instead of in the network itself.

The robustness principle is a design guideline for software that states: be conservative in what you do, be liberal in what you accept from others. It is often reworded as: be conservative in what you send, be liberal in what you accept.

Encapsulation is the computer-networking process of concatenating layer-specific headers or trailers with a service data unit for transmitting information over computer networks.