Ch.2 Data transmission Flashcards
packet
a small unit of data
packet header
a section of a packet of data that contains information about the contents of the packet and its destination
internet protocol (IP) address
the unique address that is given to a device when it is connected to a network
payload
the actual data that the user is sending to the receiver
trailer
a section of a packet of data that contains information about any error checking methods that may be used
packet switching
a method of transmitting data packets across a network
each data packet is able to take an individual pathway across the network
network
computers and devices that are joined together using cables or wireless technology
router
a network component that examines a data packet to obtain its destination address and then forward the packet to this address
serial
a transmission method where data is sent one bit at a time down a single wire
parallel
a transmission method where data is sent multiple bits at a time down multiple wires
interference
disruption, such as eletromagnetism, to data when it is transmitted
simplex
a transmission method where data is transmitted in a single direction only
half-duplex
a transmission method where data is transmitted in both directions, but only one direction at a time
full-duplex
a transmission method where data is transmitted in both directions at the same time
parity check
a type of error detection method that adds an additional bit to each byte to create an odd or even sum
checksum
a type of error detection method that performs a calculation on the data to create a checksum value
checksum values are compared after transmission to see if they match
echo check
a type of error detection method that sends a copy of the transmitted data back to the sender to be compared with the original data sent
automatic repeat request (ARQ)
a type of error detection method that uses acknowledgement and timeout to see if data has arrived correctly after transmission
acknowledgement
a message that is sent from one device to another to indicate whether data is received correctlyt
timeout
a period of time that is set and used to wait for an acknowledgement to be received
check digit
a type of error detection method that is used for data entry
a calculation is performed on the data entered to create a value
check digit values are compared to see if the data entered is correct
encryption
a method of securing data for storage or transmission that scrambles it and makes it meaningless
plain text
the name given to data before encryption
encryption key
a type of algorithm that is used to encrypt data
cipher text
the name given to data after transmission
symmetric
a type of encryption that uses the same key to encrypt and decrypt data
asymmetric
a type of encryption that uses two different keys to encrypt and decrypt data
