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DoD TCP/IP

Last Edit: 07/06/17

The development of TCP/IP was funded by DARPA, an agency of the U.S. Department of Defense (DoD), and is sometimes referred to as: DoD TCP/IP, DoD Standard, DoD Model, or the U.S. Department of Defense (DoD) Model. DARPA fund/funded technology that was designed for military use, and TCP/IP became a DoD standard for U.S. military computer networks in 1982. The process of standardising the concept of TCP/IP was contracted to two universities and one research company in the mid 1970's. DARPA founded the Internet Architecture Board (IAB) in 1983 to continue the ongoing development of TCP/IP.

However, the National Science Foundation created their own network that used the TCP/IP DoD Model in 1985 (NSFNET) and this network backbone would eventually evolve into the Internet. Eventually, the importance of the civil use of TCP/IP outweighed it's military use, and a civil organisation (Internet Society) replaced DARPA in overseeing the development of TCP/IP. However, the importance of the military's influence upon the development of the Internet can still be seen today: one of the thirteen DNS root servers (essential naming service for the Internet) is operated by the US Army (Research Lab): h.root-servers.net 198.97.190.53, 2001:500:1::53.

The TCP/IP DoD Model does have one primary competitor: the OSI Model. The TCP/IP DoD Model is a four layer model and the OSI Model is a seven layer model. During the 1980's, as each protocol competed for adoption by European computer networks, the era is referred to as the 'protocol wars'.

TCP/IP DoD Model

  1. Application Layer
  2. Transport Layer
  3. Internet Layer
  4. Link Layer

OSI Model

  1. Application Layer
  2. Presentation Layer
  3. Session Layer
  4. Transport Layer
  5. Network Layer
  6. Data Link Layer
  7. Physical Layer

Within the DoD Model the most important protocols are the Internet Protocol (IP) and Transmission Control Protocol (TCP): hence the DoD Model being simple referred to as TCP/IP. The Internet Protocol creates a format for data packets and creates an address syntax for routing data from one location to another, the Transmission Control Protocol ensures a reliable transportation of these data packets for application layer protocols that require an orderly transmission of data.

Request for Comments (RFC) documents from the early 1980's highlight the fact that when TCP/IP was standardised it was referred to as a DoD Standard.

While the documents were prepared for the Defense Advanced Research Projects Agency (DARPA),Information Processing Techniques Office, 1400 Wilson Boulevard, the documents were written by the Information Sciences Institute, University of Southern California, 4676 Admiralty Way, Marina del Rey, California (Jon Postel) and by Elizabeth Feinler, Ken Harrenstien, Zaw-Sing Su and Vic White . The fact that TCP/IP was designed and developed by U.S. academics meant that their influence would ensure that it would have a civil as well as a military use.