Early Internet Flashcards
What is multiprogramming?
1 computer = 1 running program. + n programs ready to run (on I/O wait).
What was the name of the first modem? And how many bits/s did it have?
Bell 101 (1958). 110 bits/s
What are point-to-point connections?
Many computers are connected to one terminal, but the computer are not connected.
Network of computers
Computers connected together, with all the terminals.
Store-and-forward
Connect with other computers, but not all are connected together. You need to send a message to several computers, before it reaches the right one.
Cons: Some lines of the messages can be lost in translation.
Pros: Requires fewer lines. Allows connections between computers that are not directly connected.
Packet Switching
Packets (send small boxes) switching (choose what network you want). Send messages over several computers, but cutting the messages into several packets.
Cons: Not all the messages reaches the right computers.
Pros: Very easy to send.
S+F and packet switching
Requires much fewer lines. Allows connections between computers that are not directly connected. Resilient to network reconfiguration.
What was ARPANET?
Was the one of the first networks (not the internet).
ARPANET was a network of computers connected via IMPs through dedicated phone lines, satellite lines and radio.
Todays term for ARPANET is a “router”.
What is IMP?
Interface Msg Processor.
A computer dedicated to dealing with the network. Processes messages and send it back to the main computer. Connected with a bigger computer.
What does TELENET, FTP and Email have in common?
They were the early NCP applications (Network Control Programs).
What is TCP?
Transmission Control Protocol. A communications standard that enables application programs and computing devices to exchange messages over a network.
What routes packets inside a network?
A Switch.
What routes packets between networks?
A Router.
What routes packets between networks with different technologies?
A Gateway.
What is an inter-network?
A mix of two or more independent networks.
