Explain the difference between the operation of virtual-circuit networks and
datagram networks by listing the advantages and disadvantages of each.
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Virtual-circuit networks and datagram networks are two types of network architectures that handle the transfer of data packets in different ways.
Virtual-circuit networks establish a logical connection between the sender and receiver before transmitting any data. This means that a path is predetermined and reserved for the duration of the communication session. On the other hand, datagram networks operate on a connectionless basis, where each packet is treated individually and independently.
Advantages of virtual-circuit networks:
1. Efficient use of network resources: Since a dedicated path is established, network resources are reserved for the duration of the connection, preventing congestion.
2. Guaranteed Quality of Service (QoS): Virtual-circuit networks can prioritize traffic, ensuring a consistent level of service and low latency.
3. Higher reliability: Due to the predetermined path, virtual-circuit networks offer better reliability as there is less chance of getting lost or delayed packets.
Disadvantages of virtual-circuit networks:
1. Overhead: Establishing a virtual circuit requires additional overhead in terms of signaling and session setup, which can increase latency and packet processing time.
2. Rigidity: Once a virtual circuit is created, it is fixed until the session ends, which means network changes or failures may disrupt the communication.
Advantages of datagram networks:
1. Flexibility: Datagram networks are more flexible as they do not require a dedicated path. Packets can take different routes, which allows for dynamic changes in the network.
2. Scalability: Due to their connectionless nature, datagram networks can easily adapt to changing network conditions and handle varying traffic loads.
3. Simple network infrastructure: Datagram networks do not require any additional signaling or session setup, making them less complex to implement.
Disadvantages of datagram networks:
1. Unreliable delivery: Since each packet is handled independently and there is no guaranteed QoS, there is a possibility of lost or out-of-order packets.
2. Higher network congestion: The lack of dedicated paths can lead to congestion, especially in high traffic situations.
3. Lack of flow control: Datagram networks do not have built-in mechanisms for flow control, which can result in network congestion or inefficient resource utilization.
Overall, the choice between virtual-circuit networks and datagram networks depends on the specific requirements of the application. Virtual-circuit networks are well-suited for applications that prioritize QoS and reliability, while datagram networks are preferable for applications that need flexibility and scalability.