Leased lines are an example of synchronous serial communication where one party provides the clocking
for the communication.
So in other words two devices will synchronize their clocks before data transmission takes place.
So they will align or synchronize those clocks and agree on parameters for data transfer including the
data interval between bits of data the Sea issue the issue or channel service unit data service unit
commonly referred to as the seas you provides the clocking and is the master for the communication the
right is acting as a slave and is receiving its clocking from the issue.
So essentially before communication can start the two devices have to align their clocks or agree on
the clock intervals to ensure that the data doesn't get corrupted.
So here we have the terms data communication equipment or DCP and data terminal equipment or DTV the
most in the communication is the C issue D issue and it's using its own internal clucking but the rudder
which is the data terminal equipment or DTV uses the external clocking received from the DCP and will
thus synchronize itself to the C issue D issue so the C issue D issue is the DC side of the connection
and the rudder is the DTV side of the connection.
So the DC which is the C issue D issue is providing clocking to the rudder which is the DTV and the
DC also terminates the connection from the carrier and a connection is then made from the C issue D
issue to the rudder some terms to understand therefore is customer premises equipment or CPE.
This is the term that telcos or service providers use to refer to equipment that resides at the customer
site.
At the end of their connection.
So once again in this example the C issue D issues at the customer site.
The C issue D issue which is the DCP is connected in this example via a v 35 cable to the router and
is providing clucking to the router so the C issue D issue which is the DC physically controls the speed
and timing at which the router serial interfaces can send and receive but over the serial cable.
You don't have the ability to configure the speed of your serial connection that is set by the issue
DC and is generally set by the service provider on your behalf.
The serial cable once again connects the C issue to the right interface.