Circuit switching and packet switching are the connection types that we use when sending data from one place to other.
With circuit switching we are building connection between locations so that we can send data over those lines. Circuit is established between endpoints before data passes.
Things like phone call use circuit switching, we are picking up the phone, we are dialing number, we are connecting to that site, and we are sending data, we are not able to talk to anyone else or make any other phone calls until we hang up with that connection and then we establish a new circuit to someone else.
Nobody else can use the circuit when it is idle.
Insufficient use of resources, an important consideration with circuit switching technologies, is once you build that circuit, it is in place until you tear it down, even if you’re not sending data over that connection that circuit is still in place, and those two sides are connected.
If you are sending data during a day and nothing going across the link at night, there is certain waste of resources, and that is a challenges with circuit switching. But connection is always there and it is yours, you can use connection at any time you like, and no one else can take advantage of using it.
Common circuit switching networks are things like the telephone that we use POST- plain old telephone network or PSTN –public switching telephone network lines those are effecting the same thing. So T1, E1, T3 or E3 type connection is certainly going to be used as a circuit switch where we build connection and is always going to be there.
ISDN (Integrated Services Digital Network) is a bit of an upgrade from telephone. But it still dialing a phone number and creating circuit. And that is what you’re going to send data over ISDN network.
Packet switching is how we think networking today. We take our data, we put into a wireless network or a wired network and we send a traffic on its way and it find s its destination. It might be data or video or voice, but doesn’t matter, and finding it’s way and switching based on what is in packet.
The media is usually shared, someone can use it, even when you don’t. We have many people sharing a connection to the internet (may be the internet links themselves are shared between the locations). That way we not using the connection, someone else could certainly be using exactly that connection
In this regard the internet service provider’s genellary charge us based on how much bandwidth we are going to use.
One connection may have more bandwidth than another because you paid more money, and who pay less money in a month will have less bandwidth.
Common packet switching technology are;