A two-network TCP/IP communications test was performed between Stanford and University College London (UCL), In 1975. In November, 1977, a three-network TCP/IP test was conducted between the U.S., UK, and Norway. Between 1978 and 1983, several other TCP/IP prototypes were developed at multiple computers research centres.

The full switchover to TCP/IP was performed on January 1, 1983, without too many problems, although a few recalcitrant sites were down as long as three months while they retrofitted their systems.

The TCP/IP protocol was deployed to the ARPANET network with some persuasion, as noted in the emails at the top of the page. Not all sites were preparing to convert over their protocols, so Cerf, Jon Postel, and the TCP/IP team turned off the NCP network channel numbers on the ARPANET IMP’s for a full day in mid 1982, so that only sites using TCP/IP could still operate. To emphasize the point, they disabled NCP again for two days later that fall.

In 1984, the US Department of Defense made TCP/IP the standard for all military computer networking, which gave it a high profile and stable funding.

[livinginternet.com, wikipedia.org]

what is january 1 tcp/ip? and why it is celebrated ?

On January 1st 1983, it was first came into existence and today again it reached 25 years milestone of SILVER JUBLEE ! So in the same manner this "january 1 tcp/ip" date should be remember by us forever.

Might be you wouldn't have seen this post if any kind of tcp/ip had not been invented on 1983.....so cheer up guys and again thanks to Google who always keep us updated about each and every techie movements and events.

There are three levels of TCP/IP knowledge. Those who administer a regional or national network must design a system of long distance phone lines, dedicated routing devices, and very large configuration files. They must know the IP numbers and physical locations of thousands of subscriber networks. They must also have a formal network monitor strategy to detect problems and respond quickly.

Each large company or university that subscribes to the Internet must have an intermediate level of network organization and expertise. A half dozen routers might be configured to connect several dozen departmental LANs in several buildings. All traffic outside the organization would typically be routed to a single connection to a regional network provider.

However, the end user can install TCP/IP on a personal computer without any knowledge of either the corporate or regional network. Three pieces of information are required:

The IP address assigned to this personal computer
The part of the IP address (the subnet mask) that distinguishes other machines on the same LAN (messages can be sent to them directly) from machines in other departments or elsewhere in the world (which are sent to a router machine)
The IP address of the router machine that connects this LAN to the rest of the world.

In the case of the PCLT server, the IP address is 130.132.59.234. Since the first three bytes designate this department, a "subnet mask" is defined as 255.255.255.0 (255 is the largest byte value and represents the number with all bits turned on). It is a Yale convention (which we recommend to everyone) that the router for each department have station number 1 within the department network. Thus the PCLT router is 130.132.59.1. Thus the PCLT server is configured with the values:

My IP address: 130.132.59.234
Subnet mask: 255.255.255.0
Default router: 130.132.59.1
The subnet mask tells the server that any other machine with an IP address beginning 130.132.59.* is on the same department LAN, so messages are sent to it directly. Any IP address beginning with a different value is accessed indirectly by sending the message through the router at 130.132.59.1 (which is on the departmental LAN).