Data Exchange

Packet switching Packet switching breaks data in to packets before

sending it through a network, then reassembles it at the other end – used on the internet.

Direction of data

Error control bits

Data(payload)

Packet identification

Sourceaddress

Destination address

Checks for

errors

The data

Where the data has

come from

Where data is going

Knows how to reassemble

packets

Data Exchange

VoIP and packet switching

CODECs to

encode data

Sender’s computer records a message

using webcam

and microphone

Message is converted in to digital data, broken up in to packets and sent across the internet

The received computer assembles and decodes so the data can be seen and heard

Codecs to decode data

Data Exchange

Sends data across network efficiently

Big files can be sent whole

Small packets can choose different routes through the network and move more efficiently

Security benefit - if a packet is intercepted, the hacker will only have one part of the whole file

Advantages Disadvantages If one or more packets

are lost of corrupted during transmission, the whole file will not be received correctly

Data Exchange

Transmission mode Ways in which devices on a network

communicate with each other and transmit data

Simplex – signals go in one direction

Full-Duplex – Signals go in

both directions

Half- Duplex – Signals go in both directions but the

devices don’t transmit at the

same time