Transcript Circuit & Packet Switching

Circuit & Packet
Switching
Circuit & Packet Switching
► Two
ways of achieving the same goal.
► The transfer of data across networks.
► Both methods have advantages and
disadvantages.
Circuit Switching
Circuit Switching
►A
connection path is established between
sending & receiving nodes.
► All data follows the same physical path
between sender & receiver.
► Lasts as long as it takes to transmit all data.
► ISDN & Dial-up connections
Circuit Switching
► Circuit
switched connections take time to
establish, up to 10 to 20 seconds.
► Quality can vary with each connection.
► Not efficient as communications channels
are generally not used to full capacity.
► More expensive.
Packet Switching
► Does
not establish a connection for the
entire transmission period.
► The message is divided into packets and
each individual packet can take a different
path through the network.
► Each packet is given a destination address
(IP) and sequence number (TCP).
Packet Switching
Packet Switching
► Packets
can be routed to avoid congestion
► Therefore, better bandwidth use.
► Packets from different sources can share the
same lines.
► Usually much cheaper than circuit switching.
Packet Switching
► There
is a processing overhead at the
receiving end as messages need to be
reconstructed having arrived in the wrong
order.
► Data transfer can be slower than circuit as
the connection is shared with other data.