Home > Articles > Networking > Network Design & Architecture

  • Print
  • + Share This
This chapter is from the book

PPDIOO Lifecycle Approach to Network Design and Implementation

PPDIOO stands for Prepare, Plan, Design, Implement, Operate, and Optimize. PPDIOO is a Cisco methodology that defines the continuous life-cycle of services required for a network.

PPDIOO Phases

The PPDIOO phases are as follows:

  • Prepare: Involves establishing the organizational requirements, developing a network strategy, and proposing a high-level conceptual architecture identifying technologies that can best support the architecture. The prepare phase can establish a financial justification for network strategy by assessing the business case for the proposed architecture.
  • Plan: Involves identifying initial network requirements based on goals, facilities, user needs, and so on. The plan phase involves characterizing sites and assessing any existing networks and performing a gap analysis to determine whether the existing system infrastructure, sites, and the operational environment can support the proposed system. A project plan is useful for helping manage the tasks, responsibilities, critical milestones, and resources required to implement changes to the network. The project plan should align with the scope, cost, and resource parameters established in the original business requirements.
  • Design: The initial requirements that were derived in the planning phase drive the activities of the network design specialists. The network design specification is a comprehensive detailed design that meets current business and technical requirements, and incorporates specifications to support availability, reliability, security, scalability, and performance. The design specification is the basis for the implementation activities.
  • Implement: The network is built or additional components are incorporated according to the design specifications, with the goal of integrating devices without disrupting the existing network or creating points of vulnerability.
  • Operate: Operation is the final test of the appropriateness of the design. The operational phase involves maintaining network health through day-to-day operations, including maintaining high availability and reducing expenses. The fault detection, correction, and performance monitoring that occur in daily operations provide the initial data for the optimization phase.
  • Optimize: Involves proactive management of the network. The goal of proactive management is to identify and resolve issues before they affect the organization. Reactive fault detection and correction (troubleshooting) is needed when proactive management cannot predict and mitigate failures. In the PPDIOO process, the optimization phase can prompt a network redesign if too many network problems and errors arise, if performance does not meet expectations, or if new applications are identified to support organizational and technical requirements.

Benefits of a Lifecycle Approach

The network lifecycle approach provides several key benefits aside from keeping the design process organized. The main documented reasons for applying a lifecycle approach to campus design are as follows:

  • Lowering the total cost of network ownership
  • Increasing network availability
  • Improving business agility
  • Speeding access to applications and services

The total cost of network ownership is especially important into today's business climate. Lower costs associated with IT expenses are being aggressively assessed by enterprise executives. Nevertheless, a proper network lifecycle approach aids in lowering costs by these actions:

  • Identifying and validating technology requirements
  • Planning for infrastructure changes and resource requirements
  • Developing a sound network design aligned with technical requirements and business goals
  • Accelerating successful implementation
  • Improving the efficiency of your network and of the staff supporting it
  • Reducing operating expenses by improving the efficiency of operational processes and tools

Network availability has always been a top priority of enterprises. However, network downtime can result in a loss of revenue. Examples of where downtime could cause loss of revenue is with network outages that prevent market trading during a surprise interest rate cut or the inability to process credit card transactions on black Friday, the shopping day following Thanksgiving. The network lifecycle improves high availability of networks by these actions:

  • Assessing the network's security state and its capability to support the proposed design
  • Specifying the correct set of hardware and software releases, and keeping them operational and current
  • Producing a sound operations design and validating network operations
  • Staging and testing the proposed system before deployment
  • Improving staff skills
  • Proactively monitoring the system and assessing availability trends and alerts
  • Proactively identifying security breaches and defining remediation plans

Enterprises need to react quickly to changes in the economy. Enterprises that execute quickly gain competitive advantages over other businesses. Nevertheless, the network lifecycle gains business agility by the following actions:

  • Establishing business requirements and technology strategies
  • Readying sites to support the system that you want to implement
  • Integrating technical requirements and business goals into a detailed design and demonstrating that the network is functioning as specified
  • Expertly installing, configuring, and integrating system components
  • Continually enhancing performance

Accessibility to network applications and services is critical to a productive environment. As such, the network lifecycle accelerates access to network applications and services by the following actions:

  • Assessing and improving operational preparedness to support current and planned network technologies and services
  • Improving service-delivery efficiency and effectiveness by increasing availability, resource capacity, and performance
  • Improving the availability, reliability, and stability of the network and the applications running on it
  • Managing and resolving problems affecting your system and keeping software applications current

Planning a Network Implementation

The more detailed the implementation plan documentation is, the more likely the implementation will be a success. Although complex implementation steps usually require the designer to carry out the implementation, other staff members can complete well-documented detailed implementation steps without the direct involvement of the designer. In practical terms, most large enterprise design engineers rarely perform the hands-on steps of deploying the new design. Instead, network operations or implementation engineers are often the persons deploying a new design based on an implementation plan.

Moreover, when implementing a design, you must consider the possibility of a failure, even after a successful pilot or prototype network test. You need a well-defined, but simple, process test at every step and a procedure to revert to the original setup in case there is a problem.

Implementation Components

Implementation of a network design consists of several phases (install hardware, configure systems, launch into production, and so on). Each phase consists of several steps, and each step should contain, but be not limited to, the following documentation:

  • Description of the step
  • Reference to design documents
  • Detailed implementation guidelines
  • Detailed roll-back guidelines in case of failure
  • Estimated time needed for implementation

Summary Implementation Plan

Table 1-3 provides an example of an implementation plan for migrating users to new campus switches. Implementations can vary significantly between enterprises. The look and feel of your actual implementation plan can vary to meet the requirements of your organization.

Table 1-3. Sample Summary Implementation Plan

Phase

Date, Time

Description

Implementation Details

Completed

Phase 3

12/26/2010 1:00 a.m. EST

Installs new campus switches

Section 6.2.3

Yes

Step 1

Installs new modules in campus backbone to support new campus switches

Section 6.2.3.1

Yes

Step 2

Interconnects new campus switches to new modules in campus backbone

Section 6.2.3.2

Yes

Step 3

Verifies cabling

Section 6.2.3.3

Step 4

Verifies that interconnects have links on respective switches

Section 6.2.3.4

Phase 4

12/27/2010 1:00 a.m. EST

Configures new campus switches and new modules in campus backbone

Section 6.2.4.1

Step 1

Loads standard configuration file into switches for network management, switch access, and so on

Section 6.2.4.2

Step 2

Configures Layer 3 interfaces for IP address and routing configuration on new modules in campus backbone

Section 6.2.4.3

Step 3

Configures Layer 3 interfaces for IP address and routing info on new campus switches

Section 6.2.4.4

Step 4

Configures Layer 2 features such as VLAN, STP, and QoS on new campus switches

Section 6.2.4.5

Step 5

Tests access layer ports on new campus switches by piloting access for a few enterprise applications

Section 6.2.4.6

Phase 5

12/28/2010 1:00 a.m. EST

Production implementation

Section 6.2.5

Step 1

Migrate users to new campus switches

Section 6.2.5.1

Step 2

Verifies migrated workstations can access enterprise applications

Section 6.2.5.2

Each step for each phase in the implementation phase is described briefly, with references to the detailed implementation plan for further details. The detailed implementation plan section should describe the precise steps necessary to complete the phase.

Detailed Implementation Plan

A detailed implementation plan describes the exact steps necessary to complete the implementation phase. It is necessary to includes steps to verify and check the work of the engineers implementing the plan. The following list illustrates a sample network implementation plan:

Section 6.2.4.6, "Configure Layer 2 features such as VLAN, STP, and QoS on new campus switches"

  • Number of switches involved: 8
  • Refer to Section 1.1 for physical port mapping to VLAN
  • Use configuration template from Section 4.2.3 for VLAN configuration
  • Refer to Section 1.2 for physical port mapping to spanning-tree configuration
  • Use configuration template from Section 4.2.4 for spanning-tree configuration
  • Refer to Section 1.3 for physical port mapping to QoS configuration
  • Use configuration template from Section 4.2.5 for QoS configuration
  • Estimate configuration time to be 30 minutes per switch
  • Verify configuration preferable by another engineer

This section highlighted the key concepts around PPDIOO. Although this topic is not a technical one, the best practices highlighted will go a long way with any network design and implementation plan. Poor plans will always yield poor results. Today's networks are too critical for business operations not to plan effectively. As such, reviewing and utilizing the Cisco Lifecycle will increase the likelihood of any network implementation.

  • + Share This
  • 🔖 Save To Your Account

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT and its family of brands. I can unsubscribe at any time.

Overview


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information


To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.

Surveys

Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.

Newsletters

If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information


Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.

Security


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.

Children


This site is not directed to children under the age of 13.

Marketing


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information


If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.

Choice/Opt-out


Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.informit.com/u.aspx.

Sale of Personal Information


Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents


California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure


Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.

Links


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact


Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice


We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020