When was circuit switching invented

This link only lasted until the call was complete. There are notable differences when comparing packet switching vs circuit switching. Packet switching allows users to equally share bandwidth resources but makes no promises concerning quality or latency.

Packet switching places the intelligence in the end nodes, rather than the phone company facilities, with a simple underlying network that only directs packets from one side to the other.

Packet switching is easier and more affordable than circuit switching. Everything down to the circuit board level had to be deisgned and build from scratch, along with the software in each router.

The routing decisions were carried out on a Honeywell DDP mini computer. Packet switching with its efficiency of line usage and its 'self healing' properties - being able to dynamically re-route packets around a failed router or line soon caught their attention. The first message sent over the network was on October 29th The letters 'lo' were sent before the system crashed.

Recovering from the technical problems later that day the first full message was sent and before the end of 69 the complete network of 4 IMPs was up and running. At this point the network was deemed operational rather than a research project and so control was handed over to The Defence Communications Agency.

It enabled researchers everywhere to exchange information and share computing resources with unprecedented speed, boosting collaboration and fostering a culture of open collaboration between software developers which continues to this day in the numerous open source projects which create and maintain key pieces of software which power todays Internet.

As well as scientific discussion, ARPANET also catered for more cultural and social collaboration through mailing lists covering a wide variety of interests. Many of these centres had other networks of differing sorts and the communication protocol governing the format of the packets on ARPANET known as Network Control Protocol - NCP was starting to show its weaknesses as the network expanded far beyond the size and boundaries originally envisaged.

One of the goals for the new protocol was to be able to interconnect many subnetworks of differing types so that they could all communicate as one big interconnected network or 'internet'.

Version 4 introduced in continues to be the most wideley used packet switching protocol both on the public internet and on private local area networks. Version 4 uses 32 bits for it's addresses, giving 4,,, 4.

However with the explosion in growth of the Internet over the subsequent decades and the huge number of devices now connected, that address pool is starting to run out. The Internet Society predicts that by there will be 20 billion devices on line each needing an address. A new version of IP, version 6 was standardised in the mid 90's to address the shortage of addresses by increasing the number of bits used for the address from 32 to meaning trillion trillion trillion possible addresses , and to introduce other features such as multicasting ability to send packets to multiple destinations simultaneously and security.

Whilst this may be a small amount of the total net traffic, it is double that using IPv6 when a major campaign was launched on 6th June to encourage adoption. Vinton "Vint" Cerf was born in Connecticut in After graduating from Stanford his first job was as an engineer at IBM. In Cerf and Bob Kahn co-founded the Internet Society whose mission is "to promote the open development, evolution and use of the Internet for the benefit of all people throughout the world". The Internet is successful thanks to its use of open-standards many of which are developed in a democratic way by the IETF Internet Engineering Taskforce.

By the IETF had already done a colossal amount of work on standardising the Internet technologies to promote cross platform and cross vendor interoperability yet it remained a very informal organisation from a legal perspective. It had never been incorporated as a legal entity in its own right. IETF standards are developed in an open all inclusive process which any individual can participate in and its expenses were covered by US government grants.

Baran was born in Grodno, Poland and came to the U. In , he earned his B. He based his network on a mesh network able to reconfigure itself to bypass non-working areas. To create this totally decentralized network, Baran divided the communications stream into message blocks, or "packets," sent along various paths to eventually be rejoined into a whole at their destination.