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the network architecture.
3. Layering of protocols also allows interaction between functionally paired layers
in different locations. This concept aids in permitting the distribution of functions
to remote nodes.
The terms protocol suite, protocol family, or protocol stack are used to refer to the
collection of protocols (of layers) of a particular network system.
Network Interface Cards
Network interface card, often referred to as NIC or network card, is a hardware
device that allows a computer to be connected to a network, both functionally and
physically. The NIC is a printed circuit board that is installed on to one of the
expansion slots of the computer and provides a port on the back of the computer to
which the network cable is attached. Thus, the NIC is one of the several add-on
cards (expansion boards) that the computer may have.
As the NIC is connected directly to the computer's I/O bus, the design of a NIC is
specific to the computer's I/O bus hardware, the computer's operating system, and
the network's communication protocol. The network's communication protocol is
embedded in the NIC's ROM. Thus, there are different NICs for different networks even for the same computer. For example, if a computer is to be
connected to an Ethernet LAN, it must be equipped with an Ethernet network card,
and if it is to be connected to an ATM network, it must be equipped with an ATM
In addition to the communication software embedded in the NIC's ROM, the
computer also requires network software that tells the computer how to use the
NIC. Both the network software and the NIC have to adhere to the communication
protocol of the network to which the computer is to be connected.
The OSI Model
The initial computer networks had their own set of standards and conventions that
were quite hardware oriented. Each manufacturer used to develop their own
communication protocols for their networks. For example, IBM launched SNA
(Systems Network Architecture) in 1974. Similarly, DEC (Digital Equipment
Corporation) launched its network in 1980 for use on the DEC ran...
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- Spring '14