What is the Difference between datagram network and virtual circuit network?

Answer 1

Not a whole answer but a small try :)

In a Datagram Network, there's no "network-layer-connection" between the two hosts. So Theres no garuanteed bandwith and the packets may take different paths.

In a Virutal Circuit network, its oppositly and a connection is established.

------------------------------------------------------------------------------------------------------------ •There are a number of important differences between virtual circuit and datagram networks. •The choice strongly impacts complexity of the different types of node.

•Use of datagrams between intermediate nodes allows relatively simple protocols at this level,

-but at the expense of making the end (user) nodes more complex when end-to-end virtual circuit service is desired.

•The internet transmits datagrams between intermediate nodes using IP. •Most Internet users need additional functions such as end-to-end error and sequence control to give a reliable service (equivalent to that provided by virtual circuits).

•This reliablility may be provided by

-the Transmission Control Protocol (TCP) which is used end-to-end across the Internet,

-or by applications such as the trivial file transfer protocol (tftp) running on top of the User Datagram Protocol (UDP).

Answer 2

In the virtual Circuit switching approach their is no dedicated resource allocation at the time setting up a connection between source and the receiver.

In Circuit Switching a physical path is dedicated at the time of setting up connection between source and receiver.

Answer 3

Virtual Circuit Packet Switching

1. Virtual circuits allow packets to contains circuit number instead of full destination address so less router memory and bandwidth require. Thus cost wise it is cheaper.

2. Virtual circuit requires a setup phase, which takes time and consume resources.

3. In virtual circuit, router just uses the circuit number to index into a table to find out where the packet goes.

4. Virtual circuit has some advantages in

avoiding congestion within the subnet

Because resources can be reserved in advance, when the connection is established.

5. Virtual circuit have some problem.

It a router crashes and loses its memory,

even it come back up a second later, all the

virtual circuits passing through it will have

to be aborted.

6. The loss fault on communication line

vanishes the virtual circuits.

7. In virtual circuit a fixed path is used during

transmission so traffic throughout the

subnet can not balanced. It cause congestion problem.

8. A virtual circuit is a implementation of connection oriented service.

Datagram Packet Switching

1. Datagram circuits allow packets to contains full address instead of circuit number so each packet has significant amount of overhead, and hence wasted band width. Thus it is costly.

2. Datagram circuit does not require setup phase , so no resources are consumed.

3. In datagram circuit, a more complicated procedure is required to determine where the packet goes.

4. In a datagram subnet, congestion avoidance is more difficult.

5. In datagram circuit if a router goes down only those user whose packets were queued up in the router at the time will suffer.

6. The loss or fault on communication line can be easily compensated in datagram circuits.

7. Datagram allow the router to balance the traffic throughout the subnet, since router can be changed halfway through a connection.

Answer 4

In data gram approach routing path is not fixed whereas in virtual circuit it is fixed.

in data gram all packet don't follow the same path but in virtual circuit switching all packet move from the same path

Answer 5

Datagram network mainly implies on network layers.Virtual network imply on data link layer.

Answer 6

Both are Used Packet Transmission in Internet but Datagram follows different path for different packet but single data, in virtual ckt follows same path for single data