Hitachi US7070447-001 User Manual
Doc Part Number, Version Number
5-
1
Chapter 5
Fundamentals of Networking
Today, there are many different types of computers and networking
equipment available. These devices are expected to communicate with
each other. For this reason, it is extremely important that a set of rules be
established and implemented in order for networking devices to function
well together.
equipment available. These devices are expected to communicate with
each other. For this reason, it is extremely important that a set of rules be
established and implemented in order for networking devices to function
well together.
In 1978, the International Standards Organization (ISO) defined the Open
System Interconnection (OSI) Model for networking. This reference
model outlines the communications protocols used when transporting data
from one network node to another. The standard was initially written to
provide both hardware and software vendors a common platform on which
to develop products. The model also serves as the basis for the IEEE LAN
standards.
System Interconnection (OSI) Model for networking. This reference
model outlines the communications protocols used when transporting data
from one network node to another. The standard was initially written to
provide both hardware and software vendors a common platform on which
to develop products. The model also serves as the basis for the IEEE LAN
standards.
The OSI Model divides the task of computer communications into seven
layers. The model represents a hierarchical structure and is designed so
that each layer performs a specific service transparently to layer above and
below it. In addition, the corresponding layers between two adjacent
devices communicate to each other in a peer to peer relationship.
layers. The model represents a hierarchical structure and is designed so
that each layer performs a specific service transparently to layer above and
below it. In addition, the corresponding layers between two adjacent
devices communicate to each other in a peer to peer relationship.
The Figure 5-1 shows the seven layers in the OSI Model in a peer-to-peer
relationship
relationship