2. Differences between Packet switching and circuit switching.

Circuit Switching is the basis of a conventional telephone system. A circuit between two user must established for a communication to occur and it must maintained for the duration of the call until one of the party hang up. This network need resources to be reserved for each pair of end user. Also, there must be no other user that can use the already dedicated resources for the duration of network use.

Circuit switching is ideal when data must be transmitted quickly, arrive at a sequence order and at a constant rate. So, it is used for audio, video and real time application. This type of network is establish as a virtual circuit between endpoints and the single route which does not vary during connection and the nest connection may take a difference route.

The following diagram show an example of circuit switching network. In the diagram, the communication link is set by thick blue line for the conduit of data from device A to device B and a matching purple line form B to A. Once set up, all communication between devices take plcaes over the conduit , even though there are possible ways that data could be conceivably passed over the network of devices between them.









Fig 1 Circuit Switching Network


Packet switched network is a unified, integrated data between infrastructure that can provide a variety of communication services that needs a different bandwidth.. It keeps the connection long enough to send packets form one end to the other. It is used for the integration and transmission of voice and data . Besides that, it span a large geographical are and comprise a web switching nodes interconnected through transmission links. It allocate resources when required.

The following diagram show a packet switching network. In this network, no circuit is set to prior to sending data between devices. Blocks of data, even from the same file, may take any number of paths as it journey form one devices to another


Fig2 Packet Switching network

The advantage of packet switching is that both parties can transmit at different rates. But the problem is that too many packets can cause congestion and packets that cannot be stored or delivered might be discarded by the packet switching exchange.

VoIP uses packet switching as It needs to send those voice packets at a faster rate while the conventional telephone uses a circuit where it needs dedicated path between two user.