Think how things would be if you could only use your telephone to talk to just one other person! You would not be very productive. So there are requirements for switching systems to route your calls around the world.
There are a number of ways to perform switching:
- Circuit Switching
- Packet Switching
- Message Switching
- Cell Switching
- This method involves the physical interconnection of two devices.
- A good example of circuit switching involves the Public phone network.
- A data example would be the classic A/B switch!
- Packet Switching techniques switch packets of data between destinations.
- Traditionally this applied to X.25 techniques, but also applies to TCP/IP and IPX/SPX routers.
- Proprietary Frame Relay switches can switch voice signals.
- Message Switching techniques were originally used in data communications.
- An example would be early “store and forward” paper tape relay systems.
- E-Mail delivery is another example of message switching.
- In voice systems, you can find Voice Mail delivery systems on the Internet.
- The classic “forward voice mail” capability in some voice mail systems is another example.
- Cell Switching is similar to packet switching, except that the switching does not necessarily occur on packet boundaries.
- This is ideal for an integrated environment and is found within Cell-based networks, such as ATM.
- Cell-switching can handle both digital voice and data signals.