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Unformatted text preview: es - circuit establishing, data transfer
and circuit disconnection. It is used in the Public Switched Telephone Network
1. The main advantage of circuit switching is that once the circuit is established,
data is transmitted with no delay other than the propagation delay, which is
negligible (typically of the order of 6 msec per 1000 kms).
2. It is suitable for low-speed communication between a terminal and a computer
because the method is simple and requires no special facilities.
3. Since a dedicated continuous transmission path is established, the method is
suitable for long continuous transmissions.
Since the full capacity of the circuit is available for exclusive use by the
connected pair of nodes, the transmission time required to send a message can be
known and guaranteed after the circuit has been successfully established. Hence
it is the preferred method for transmission of voice and real-time data.
Prior to actual data transfer, the time required to establish a physical link
between the two stations is of the order of 10 sees or more depending on the
distance. For many computer applications, such as point of sale verification, this
elapse time is too large and unsuitable.
2. Since the physical link is a dedicated one, the channel capacity is dedicated to
one source for the entire duration of a connection. Hence, the network resources
are not properly utilized.
3. Since communications between computers occur in short fast bursts with long
silent periods in between (during which the communication line is not used), the
method proves to be very uneconomical when used for communication between
computers that are connected using expensive, high-speed transmission lines.
A message is a logical unit of information and can be of any length. In this
method, if a station wishes to send a message to another station, it first appends
the destination address to the message. After this, the message is transmitted fro...
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This document was uploaded on 04/07/2014.
- Spring '14