Early Networks
ARPANET and SITA HLN became operational in 1969. Before the introduction of X.25 in 1973, about twenty different network technologies were developed. There was a debate about the merits of two drastically different views as to proper division of labor between the hosts and the network. In the datagram system the host must detect loss or duplication of packets. Transmission Control Protocol /Internet Protocol (TCP/IP) is the best known example of a host to datagram protocol. In the virtual call system, the network guarantees sequenced delivery of data to the host. This results in a simpler host interface with less functionality than in the datagram model. X.25 is the best known virtual call protocol.
Inexpensive minicomputers were an important component in the early networks. In some cases custom I/O devices were added to allow inexpensive or exotic attachments to communication lines.
Read more about this topic: Packet-switched Network
Famous quotes containing the words early and/or networks:
“A two-year-old can be taught to curb his aggressions completely if the parents employ strong enough methods, but the achievement of such control at an early age may be bought at a price which few parents today would be willing to pay. The slow education for control demands much more parental time and patience at the beginning, but the child who learns control in this way will be the child who acquires healthy self-discipline later.”
—Selma H. Fraiberg (20th century)
“To be perfectly, brutally honest, those of us who are still carrying diaper everywhere we go are not at our most scintillating time of life....We need to remember that at one time in our lives, we all had senses of humor and knew things that were going on in the world. And if we just keep our social networks open, there will be people ready to listen when we once again have intelligent things to say.”
—Louise Lague (20th century)