There are several aspects involved in characterizing the infrastructure of a
network:
- Developing a network map

- Learning the location of major internetworking devices and network segments
- Documenting the names and addresses of major devices and segments
- Identifying any standard methods for addressing and naming
- Documenting the types and lengths of physical cabling
- Investigating architectural and environmental constraints
To develop an understanding of traffic flow, learn the location of
major hosts, interconnection devices, and network segments. A combination of
information on the performance characteristics of network segments and location
information provides insight into where users are concentrated and the level of
traffic a network design must support.
At this point in the network
design process, the goal is to obtain a map of the existing network. Some
design customers may have maps for the new network design as well. However,
avoid using any assumptions that are not based on a detailed analysis of
business and technical requirements.
Not all customers can provide a
detailed and up-to-date map of the existing network. Companies that are
constantly reacting to situations do not have time to completely document the
existing network.
While surveying a facility and deciding where the APs
should be located, look for ways to connect the APs to the network. By this
point, the network layout and components should be well understood and the SE
should have a good idea of where and how to interface with the network. Most
SEs are not experts on cabling. The SE’s job is to perform the survey and make
recommendations. These recommendations must include the cabling associated with
the APs. Because of this, some knowledge of cabling is necessary. Some of the
issues surrounding cabling will be addressed for a general awareness of the
items to be concerned with during the survey.
The number one rule when
designing the cable portion of the WLAN is to avoid creating a fire hazard.
This requires designing the cable runs properly. The customer may choose to
ignore the cabling recommendations. This is why accurate documentation is
necessary. In the future, proof may be needed to show that the installed
cabling was not the same as the recommended cabling. Without proper
documentation, this will be very difficult to prove. However, if a faulty
system is designed and installed according to the recommendations of the SE,
the SE would be held responsible.
When investigating cabling, pay
attention to environmental issues such as cabling that will run near creeks
that could flood, railroad tracks and highways where traffic could jostle
cables, or construction and manufacturing areas where heavy equipment or
digging could break cables. Within buildings, pay attention to architectural
issues that could affect the feasibility of implementing the network design.
Make sure the architectural elements listed in Figure
are
sufficient to support the design.