Virtual Circuits or Connectionless Datagrams?

Now we know we can get packets from one device to another, we are faced with a philosophical argument.

Do we put packets out on the network with the destination address and hope they get there (the Internet)?

Or do we create a virtual circuit (VC) through the network which is always up and can provide guarantees (the phone network and legacy protocols like ATM)?

This argument swings to either side periodically.

Now, most of our networks are packet based and do not use virtual circuits; however, you may come across technology which does.

We will see in later sessions that we can make our layer 3 protocols connection-oriented using layer 4/5 protocols like TCP (Transmission Control Protocol).