comparison of Virtual circuit and datagram subnets

Virtual Circuit vs Datagram Subnets:

1. Connection:

   • Virtual Circuit: It is a connection-oriented network. Before data transmission, a path (circuit) is established between the sender and receiver.
   • Datagram Subnets: It is a connectionless network. Each packet is treated independently. There is no need to establish a connection before sending data.

2. Routing:

   • Virtual Circuit: All packets follow the same path established during the connection. The path remains the same until the connection is terminated.
   • Datagram Subnets: Each packet can take a different path to reach the destination. The route can change dynamically based on network conditions.

3. Packet Order:

   • Virtual Circuit: Packets arrive in the order they were sent because they all follow the same path.
   • Datagram Subnets: Packets may arrive out of order as they can take different paths and some paths may be faster than others.

4. Resource Allocation:

   • Virtual Circuit: Resources are allocated during the connection establishment. This can lead to efficient utilization but also to resource wastage if the connection is idle.
   • Datagram Subnets: Resources are allocated on a per-packet basis. This can lead to better resource utilization but also to higher overhead due to continuous allocation and deallocation.

5. Reliability:

   • Virtual Circuit: It is more reliable as the connection is established before data transmission and all packets follow the same path.
   • Datagram Subnets: It is less reliable as packets can take different paths and may arrive out of order or get lost.

6. Implementation:

   • Virtual Circuit: It is more complex to implement due to the need for connection establishment and maintenance.
   • Datagram Subnets: It is simpler to implement as each packet is treated independently.

7. Examples:

   • Virtual Circuit: Frame Relay, ATM
   • Datagram Subnets: Internet Protocol (IP)