Specifications

Chapter 1 Understanding Networking and IP Addressing
Introduction to Networking
Niagara Release 2.3
Niagara Networking & Connectivity Guide Revised: May 22, 2002
1–9
Connectors As discussed earlier, there is a variety of different types of networking cables and
there are various ways to connect them. To select the appropriate interface card for a
network, determine the type of cabling and connectors required to support the
connection. Keep in mind that some NICs come with more than one interface
connector, which can be selected by either jumper or software setting.
The OSI Model and the IEEE 802 Standards
Every discussion of network communications includes a discussion of the ISO Open
Systems Interconnection (OSI) model. The reason that this model is so important is
that it provides a complete model of the functions of a communications system so that
different vendors, if they build components that conform to the model, should be able
to intercommunicate.
The OSI Model In 1978, the International Standards Organization (ISO) released specifications that
describe a network architecture for connecting dissimilar devices. The specification
applied rules to systems so that they would use the same protocol and standards to
exchange information.
In 1984, the ISO revised the specification and called it the Open Systems
Interconnection (OSI) reference model. The 1984 revision has become an
internationally accepted standard for networking—the OSI model has become the
best known and most widely used guide to describe networking environments.
Vendors design network products based on the specification of the OSI model, which
provides a description of how network hardware and software work together in a
layered fashion to make network communications possible.
Layered
Architecture
The OSI model is an architecture that divides network communications into seven
layers. Each layer applies to different network activities, equipment, or protocols.
Control is passed from one layer to the next, starting at the application layer in one
Table 1-2 Connector types.
T-connector, used with 10Base2 networks.
RJ-11 (4-pin), RJ-45 (8-pin). RJ-45 connectors are used with 10BaseT and
100BaseT networks.
BNC. BNC connectors are used with 10Base2 networks.
D-shell
Fiber, used with 10BaseFL networks.