Information Technology Reference
In-Depth Information
Ta b l e 1-7
PPDIOO Network Life Cycle Phases
PPDIOO Phase
Description
Prepare
Establishes organization and business requirements, develops a network
strategy, and proposes a high-level architecture
Plan
Identifies the network requirements by characterizing and assessing the
network, performing a gap analysis
Design
Provides high availability, reliability, security, scalability, and performance
Implement
Installation and configuration of new equipment
Operate
Day-to-day network operations
Optimize
Proactive network management; modifications to the design
Design Methodology Under PPDIOO
The following sections focus on a design methodology for the first three phases of the
PPDIOO methodology. This design methodology has three steps:
Step 1.
Identifying customer network requirements
Step 2.
Characterizing the existing network
Step 3.
Designing the network topology and solutions
In Step 1, decision makers identify requirements, and a conceptual architecture is pro-
posed. This step occurs in the PPDIOO Prepare phase.
In Step 2, the network is assessed, and a gap analysis is performed to determine the infra-
structure necessary to meet the requirements. The network is assessed on function, per-
for mance, and qualit y. This step occ ur s in the PPDIOO Plan phas e.
In Step 3, the network topology is designed to meet the requirements and close the net-
work gaps identified in the previous steps. A detailed design document is prepared during
this phase. Design solutions include network infrastructure, Vo i c e over IP (VoIP), content
networking, and intelligent network services. This set occurs in the PPDIOO Design phase.
To o b t a i n c u s t o m e r r e q u i r e m e n t s , y o u n e e d t o n o t o n l y t a l k t o n e t w o r k e n g i n e e r s , b u t a l s o
talk to business unit personnel and company managers. Networks are designed to support
applications; you want to determine the network services that you need to support.
As shown in Figure 1-5, the steps to identify customer requirements are as follows:
Step 1.
Identify network applications and services.
Step 2.
Define the organizational goals.
Step 3.
Define the possible organizational constraints.
Step 4.
Define the technical goals.
Step 5.
Define the possible technical constraints.
