TCP/IP vs. OSI

The need for a networking standard

In the late 20th century, different computer networks used incompatible systems, creating a need for a universal networking standard.

Two standards were promoted to become the foundation of global networking:

• OSI (Open Systems Interconnection)
• TCP/IP (Transmission Control Protocol/Internet Protocol)

The development of OSI

OSI originated from the International Organization for Standardization (ISO):

• ISO launched the OSI effort in 1977
• the OSI reference model was agreed upon in 1982 and published in 1984
• its goal was to standardize communication between different computer systems

OSI received strong international and institutional support:

• European governments and manufacturers backed it
• U.S. agencies such as NIST and the Department of Defense supported it
• many believed OSI would become the global networking standard

TCP/IP becomes the Internet standard

TCP/IP gradually became more successful because:

• it was simpler and already working on real networks
• OSI protocols were considered too complex
• the OSI standardization process became slow and bureaucratic

TCP/IP development used a more flexible and open process:

• engineers collaborated through the Request for Comments (RFC) system
• the focus was on practical solutions and working code

Even while governments officially supported OSI, many universities and national networks adopted TCP/IP because it was more effective in practice.

The U.S. Department of Defense strongly backed TCP/IP from the ARPANET era onward, giving it a large installed base before OSI was fully standardized.

By the early 1990s, TCP/IP became the dominant standard and the foundation of the modern Internet.

The success of TCP/IP influenced Internet governance:

• it encouraged a bottom-up, multi-stakeholder engineering culture
• standards became based more on practical effectiveness than government mandates
• since many TCP/IP contributors were American, it also reinforced perceptions of U.S. influence over Internet standards

The lasting influence of the OSI model

Although OSI protocols failed, the OSI seven-layer model remained influential.

Today it is still widely used for teaching and understanding networking concepts.