Securing Protocol Layers   «Prev  Next»

Physical Data Link Layers

TCP/IP Protocols

The following definitions hold true for TCP/ IP Protocols:
  1. Internet protocol, Uses addressing to find a route so that datagrams reach the correct destination
  2. Transport protocol, Breaks information into datagrams and ensures that all datagrams arrive correctly
  3. Address resolution protocol, Converts IP addresses to physical network addresses by broadcasting an address request
  4. Internet control message protocol, Used to communicate errors or other conditions at the IP layer

The Internet protocol suite is the networking model and a set of communications protocols used for the Internet and similar networks.
It is commonly known as TCP/IP, because its most important protocols, the Transmission Control Protocol (TCP) and the Internet Protocol (IP), were the first networking protocols defined in this standard. It is occasionally known as the DoD model, because the development of the networking model was funded by DARPA, an agency of the United States Department of Defense. TCP/IP provides end-to-end connectivity specifying how data should be formatted, addressed, transmitted, routed and received at the destination.
This functionality has been organized into four abstraction layers which are used to sort all related protocols according to the scope of networking involved. From lowest to highest, the layers are the
  1. link layer,
  2. containing communication technologies for a single network segment (link),
  3. the internet layer,
  4. connecting independent networks,
  5. thus establishing internetworking,
  6. the transport layer handling process-to-process communication,
  7. and the application layer, which interfaces to the user and provides support services.