Although all network design projects will ultimately involve a very careful and thorough analysis of the existing network, a great deal of information is often provided in advance by the customer. Sometimes this information is limited to what has been provided in the RFP and RFI documents, while in others, large amounts of supplementary documentation may be passed to the designer. While this provides a useful introduction to the existing environment, documentation can often be well out of date, incorrect, or misleading. For that reason, documentation provided by the customer should never be assumed to be complete and/or accurate.
By the same token, understanding a customer’s existing network will usually involve interviews with various staff and management. Where documentation generally provides the details of an existing implementation, interviews can often help to uncover the rationale for various decisions that were made. Again, the information that is gathered about the existing network from various staff members can seldom be considered entirely complete or accurate. Here again, people have points of view and opinions, and their perspective may not accurately reflect the true current situation.
Conducting interviews and using examining existing documentation are almost always the first steps in attempting to characterize a customer’s existing network. However, always keep in mind that this is generally the least accurate of the different types of information you will collect as part of your assessment.