10 Chapter 1: Design Overview
in the decision-making process. Find out how the customer assigns authority with regard to
information resources. Do your best to understand the customer and their needs.
NOTE
The best source of information about performance requirements is the people who use the
system. Be sure to include user groups to ensure that no one is left out of the design process.
Analyze Requirements
Determine the customer's business requirements. As soon as you understand the business goals,
you can determine the type of technology that is needed. Determine the network availability
requirements and the acceptable mean time between failures. Each customer will have a
different definition of availability. Adding more resources can increase availability. However,
resources increase cost. At some point, greater availability yields a lower output because of
the increased cost of providing it. Internetwork design provides the greatest availability for the
least cost.
Other requirements include the following:
·
Security--Determine the amount of security that this design requires.
·
Disaster recovery
·
Application characteristics--Determine the types of applications that the network will
serve:
-- Which ones are bandwidth-intensive, and how much bandwidth do they require?
-- Do any applications require multicasting?
·
Users--Determine the number of users who will access the network.
-- Which customers have special needs?
-- What are the peak times for network usage and its load?
NOTE
Be aware of the corporate culture and how it impacts the decision-making process. The best-
planned network design might not be accepted if the president's uncle is in the network business
and has different ideas.
87200333.book Page 10 Wednesday, August 22, 2001 2:18 PM