| Data Network Identification Code |
Website Links For Packet |
Information AboutData Network Identification Code |
| CATEGORIES ABOUT PACKET SWITCHED NETWORK | |
| network protocols | |
| packets | |
|
A Packet Switched Network, or PSN, refers to the packet switched networks that existed before Internet. History can be divided into three eras: early networks before the introduction of X.25 and OSI , the X.25 era when many Postal Telephone And Telegraph (PTT) companies introduced networks with X.25 interfaces, and the Internet era when restrictions on connection to the Internet were removed. EARLY NETWORKS ARPANET and SITA HLN became operational in 1969. Before the introduction of X.25 in 1969, about twenty different network technologies were developed. There was a debate about the merits of two drastically different views as to proper division of labour 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 Minicomputer s 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. Arpanet See Also: ARPANET This is the principal survivor from the early era. TCP/IP which was an important component of ARPANET2 was chosen for use in NSFNET which eventually became the Internet. BNRNET BNRNET was a network which Bell Northern Research developed for internal use. It initially had only one host but was designed to support many hosts. BNR later made major contributions to the CCITT X.25 project. |
|
|