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This chapter begins with an introduction to the Cisco vision of intelligent networks and the Service Oriented Network Architecture (SONA) architectural framework. The lifecycle of a network and a network design methodology based on the lifecycle are presented. Each phase of the network design process is explored in detail, starting with how to identify customer requirements, including organizational and technical goals and constraints. Because many customers build on an existing network and at existing sites, this chapter also presents methods of characterizing that existing network and those sites. A top-down approach to design and structured design principles is presented. The design process includes a discussion about building a prototype or pilot and the appropriate content of a design specification. The chapter concludes with a discussion of the design implementation process.

Add a note here The Cisco Service Oriented Network Architecture

Add a note hereThe extremely rich variety of application-level business solutions available today and the need to integrate these applications drives the need for a new network architecture. This section introduces the Cisco Vision and Framework that enable customers to build a more intelligent network infrastructure. The Cisco SONA architectural framework shifts the view of the network from a pure traffic transport-oriented view toward a service- and application-oriented view.

Add a note here Business Drivers for a New Network Architecture

Add a note hereNew business requirements, the growth of applications, and the evolution of IT combine to drive the need for a new network architecture. In today’s business environment, intense competition and time-to-market pressures are prompting enterprises to look for new IT solutions that can help them better respond to market and customer demands. Consumers are asking for new products and service offerings—and they want them fast. They are also demanding improved customer service, enhanced customization flexibility, and greater security, all at a lower cost.

Add a note hereModern networks connect multiple resources and information assets within the organization as well as provide access to external resources. In this environment, the IT model has evolved from mainframes, to client/server models, to Internet applications, as illustrated in Figure 2-1. The Cisco vision of the next phase of IT evolution is a real-time infrastructure that integrates the network and the applications as one system.

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Add a note hereFigure 2-1: IT Evolution from Connectivity to Intelligent Systems

Add a note here Organizations are finding that networking is no longer just about connectivity; rather, network intelligence is starting to play a role in improving business performance and processes. Intelligence enhances the network’s role as a foundation for enabling communication, collaboration, and business success. With increased awareness of the applications that operate on the network foundation, the network becomes an active participant in applications, network management, business systems, and services to enable them to work better.

Add a note hereThe network is the common single element that connects and enables all components of the IT infrastructure.

Add a note hereOrganizations need their networks to evolve to intelligent systems that participate actively in the delivery of applications to effectively reach the goals of improved productivity, reduced time to market, greater revenue, lower expenses, and stronger customer relationships. An effective network provides the foundation for transforming business practices.

Add a note here Intelligence in the Network

Add a note hereIntegrating intelligence into the network involves aligning network and business requirements. To accommodate today’s and tomorrow’s network requirements, the Cisco vision of the future includes the Intelligent Information Network (IIN), a strategy that addresses how the network is integrated with businesses and business priorities. This vision encompasses the following features:

  • Add a note here Integration of networked resources and information assets that have been largely unlinked: The modern converged networks with integrated voice, video, and data require that IT departments (and other departments traditionally responsible for other technologies) more closely link the IT infrastructure with the network.

  • Add a note here Intelligence across multiple products and infrastructure layers: The intelligence built in to each component of the network is extended networkwide and applies end-to-end.

  • Add a note here Active participation of the network in the delivery of services and applications: With added intelligence, it is possible for the network to actively manage, monitor, and optimize service and application delivery across the entire IT environment.

Add a note hereWith this technology vision, Cisco is helping organizations address new IT challenges, such as the deployment of service-oriented architectures, web services, and virtualization (as described in the upcoming Phase 2 bullet). This vision offers an evolutionary approach that consists of three phases in which functionality can be added to the infrastructure as required. The three phases are illustrated in Figure 2-2 and described as follows:

  • Add a note here Phase 1: Integrated transport: Everything (data, voice, and video) consolidates onto an IP network for secure network convergence. By integrating data, voice, and video transport into a single standards-based modular network, organizations can simplify network management and generate enterprisewide efficiencies. Network convergence also lays the foundation for a new class of IP-enabled applications, now known as Cisco Unified Communications solutions.


    Note

    Add a note here Cisco Unified Communications is the name, launched in March 2006, for the entire range of what were previously known as Cisco IP communications products. These include all call control, conferencing, voice mail and messaging, customer contact, IP phone, video telephony, videoconferencing, rich media clients, and voice application products.

  • Add a note here Phase 2: Integrated services: When the network infrastructure is converged, IT resources can be pooled and shared, or virtualized, to flexibly address the changing needs of the organization. By extending this virtualization concept to encompass server, storage, and network elements, an organization can transparently use all its resources more efficiently. Business continuity is also enhanced because in the event of a local systems failure, shared resources across the intelligent network can provide needed services.

  • Add a note here Phase 3: Integrated applications: This phase focuses on making the network application-aware so that it can optimize application performance and more efficiently deliver networked applications to users. In addition to capabilities such as content caching, load balancing, and application-level security, application network services make it possible for the network to simplify the application infrastructure by integrating intelligent application message handling, optimization, and security into the existing network.

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Add a note hereFigure 2-2: Intelligence in the Network

Note

Add a note hereYou can access the IIN home page at http://www.cisco.com/go/iin.


Note

Add a note hereThe IT industry is currently deploying Phase 2 integrated services. With Application-Oriented Networking technology, Cisco has entered Phase 3, and the industry is starting to define Phase 3 integrated applications.

Add a note here Cisco SONA Framework

Add a note hereThe Cisco SONA is an architectural framework that illustrates how to build integrated systems and guides the evolution of enterprises toward more intelligent networks. Using the SONA framework, enterprises can improve flexibility and increase efficiency by optimizing applications, business processes, and resources to enable IT to have a greater effect on business.

Add a note hereThe SONA framework leverages the extensive product-line services, proven architectures, and experience of Cisco and its partners to help enterprises achieve their business goals.

Add a note here The SONA framework, shown in Figure 2-3, shows how integrated systems can allow a dynamic, flexible architecture and provide for operational efficiency through standardization and virtualization.

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Add a note hereFigure 2-3: Cisco SONA Framework

Add a note hereThe SONA framework defines the following three layers:

  • Add a note here Networked Infrastructure layer: Where all the IT resources are interconnected across a converged network foundation. The IT resources include servers, storage, and clients. The Networked Infrastructure layer represents how these resources exist in different places in the network, including the campus, branch, data center, enterprise edge, WAN, metropolitan-area network (MAN), and with the teleworker. The objective of this layer is to provide connectivity, anywhere and anytime.

    Add a note hereThe Networked Infrastructure layer includes the network devices and links to connect servers, storage, and clients in different places in the network.

  • Add a note here Interactive Services layer: Includes both application networking services and infrastructure services. This layer enables efficient allocation of resources to applications and business processes delivered through the networked infrastructure. This layer includes the following services:

    • Add a note hereVoice and collaboration services

    • Add a note hereMobility services

    • Add a note hereWireless services

    • Add a note hereSecurity and identity services

    • Add a note hereStorage services

    • Add a note hereCompute services

    • Add a note hereApplication networking services (content networking services)

    • Add a note hereNetwork infrastructure virtualization

    • Add a note hereAdaptive network management services

    • Add a note hereQuality of service (QoS)

    • Add a note hereHigh availability

    • Add a note hereIP multicast

  • Add a note here Application layer: This layer includes business applications and collaboration applications. The objective of this layer is to meet business requirements and achieve efficiencies by leveraging the interactive services layer. This layer includes the following collaborative applications:

    • Add a note hereInstant messaging

    • Add a note hereCisco Unified Contact Center

    • Add a note hereCisco Unity (unified messaging)

    • Add a note hereCisco IP Communicator and Cisco Unified IP Phones

    • Add a note hereCisco Unified MeetingPlace

    • Add a note hereVideo delivery using Cisco Digital Media System

    • Add a note hereIP telephony


Note

Add a note hereThe preceding lists include voice as an infrastructure service and IP telephony as an application. Note that some Cisco documentation uses the term IP telephony to describe the infrastructure service supported by other services, such as voice. To avoid ambiguity, the term IP telephony is used in this book to describe the network application supported by other services, such as voice.

Add a note here Figure 2-4 illustrates some of these SONA offerings within each of the layers.

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Add a note hereFigure 2-4: Cisco SONA Offerings

Note

Add a note here You can access the SONA home page at http://www.cisco.com/go/sona.

Add a note hereThe benefits of SONA include the following:

  • Add a note here Functionality: Supports the organizational requirements.

  • Add a note here Scalability: Supports growth and expansion of organizational tasks by separating functions and products into layers; this separation makes it easier to grow the network.

  • Add a note here Availability: Provides the necessary services, reliably, anywhere, anytime.

  • Add a note here Performance: Provides the desired responsiveness, throughput, and utilization on a per-application basis through the network infrastructure and services.

  • Add a note here Manageability: Provides control, performance monitoring, and fault detection.

  • Add a note here Efficiency: Provides the required network services and infrastructure with reasonable operational costs and appropriate capital investment on a migration path to a more intelligent network, through step-by-step network services growth.

  • Add a note here Security: Provides for an effective balance between usability and security while protecting information assets and infrastructure from inside and outside threats.


Network Design Methodology

Add a note here The network design methodology presented in this section is derived from the Cisco Prepare, Plan, Design, Implement, Operate, and Optimize (PPDIOO) methodology, which reflects a network’s lifecycle. The following sections describe the PPDIOO phases and their relation to the network design methodology, and the benefits of the lifecycle approach to network design. Subsequent sections explain the design methodology in detail.

Add a note here Design as an Integral Part of the PPDIOO Methodology

Add a note hereThe PPDIOO network lifecycle, illustrated in Figure 2-5, reflects the phases of a standard network’s lifecycle. As shown in this figure, the PPDIOO lifecycle phases are separate, yet closely related.

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Add a note hereFigure 2-5: PPDIOO Network Lifecycle Influences Design

Add a note here The following describes each PPDIOO phase:

  • Add a note here Prepare phase: The Prepare phase involves establishing the organizational (business) requirements, developing a network strategy, and proposing a high-level conceptual architecture, identifying technologies that can best support the architecture. Financial justification for the network strategy is established by assessing the business case for the proposed architecture.

  • Add a note here Plan phase: This phase involves identifying the network requirements, which are based on the goals for the network, where the network will be installed, who will require which network services, and so forth. The Plan phase also involves assessing the sites where the network will be installed and any existing networks, and performing a gap analysis to determine if the existing system infrastructure, sites, and operational environment can support the proposed system. A project plan helps manage the tasks, responsibilities, critical milestones, and resources required to implement the changes to the network. The project plan should align with the scope, cost, and resource parameters established in the original business requirements. The output of this phase is a set of network requirements.

  • Add a note here Design phase: The initial requirements determined in the Plan phase drive the network design specialists’ activities. These specialists design the network according to those initial requirements, incorporating any additional data gathered during network analysis and network audit (when upgrading an existing network) and through discussion with managers and network users. The network design specification that is produced is a comprehensive detailed design that meets current business and technical requirements and incorporates specifications to support availability, reliability, security, scalability, and performance. This design specification provides the basis for the implementation activities.

  • Add a note here Implement phase: Implementation and verification begins after the design has been approved. The network and any additional components are built according to the design specifications, with the goal of integrating devices without disrupting the existing network or creating points of vulnerability.

  • Add a note here Operate phase: Operation is the final test of the design’s appropriateness. The Operate phase involves maintaining network health through day-to-day operations, which might include maintaining high availability and reducing expenses. The fault detection and correction and performance monitoring that occur in daily operations provide initial data for the network lifecycle’s Optimize phase.

  • Add a note here Optimize phase: The Optimize phase is based on proactive network management, the goal of which is to identify and resolve issues before real problems arise and the organization is affected. Reactive fault detection and correction (troubleshooting) are necessary when proactive management cannot predict and mitigate the failures. In the PPDIOO process, the Optimize phase might lead to network redesign if too many network problems or errors arise, if performance does not meet expectations, or if new applications are identified to support organizational and technical requirements.

Add a note hereAlthough Design is one of the six PPDIOO phases, all the other phases influence design decisions, and the Design phase interacts closely with them, as follows:

  • Add a note hereThe requirements derived from the Prepare and Plan phases are the basis for network design.

  • Add a note hereThe Implement phase includes the initial verification of the design on the actual network.

  • Add a note hereDuring the Operate and Optimize phases, the final decision is made about the appropriateness of the design, based on network analysis and any problems that arise. The network might have to be redesigned to correct any discovered errors.

Add a note here Benefits of the Lifecycle Approach to Network Design

Add a note hereThe network lifecycle approach provides many benefits, including the following:

  • Add a note here Lowering the total cost of network ownership:

    • Add a note hereIdentifying and validating technology requirements

    • Add a note herePlanning for infrastructure changes and resource requirements

    • Add a note hereDeveloping a sound network design aligned with technical requirements and business goals

    • Add a note hereAccelerating successful implementation

    • Add a note hereImproving the efficiency of the network and of the staff supporting it

    • Add a note hereReducing operating expenses by improving the efficiency of operation processes and tools

  • Add a note here Increasing network availability:

    • Add a note hereAssessing the state of the network’s security and its ability to support the proposed design

    • Add a note hereSpecifying the correct set of hardware and software releases and keeping them operational and current

    • Add a note hereProducing a sound operational design and validating network operation

    • Add a note hereStaging and testing the proposed system before deployment

    • Add a note hereImproving staff skills

    • Add a note hereProactively monitoring the system and assessing availability trends and alerts

    • Add a note hereProactively identifying security breaches and defining remediation plans

  • Add a note here Improving business agility:

    • Add a note hereEstablishing business requirements and technology strategies

    • Add a note hereReadying sites to support the system to be implemented

    • Add a note hereIntegrating technical requirements and business goals into a detailed design and demonstrating that the network is functioning as specified

    • Add a note hereExpertly installing, configuring, and integrating system components

    • Add a note hereContinually enhancing performance

  • Add a note here Accelerating access to applications and services:

    • Add a note hereAssessing and improving operational preparedness to support current and planned network technologies and services

    • Add a note hereImproving service-delivery efficiency and effectiveness by increasing availability, resource capacity, and performance

    • Add a note hereImproving the availability, reliability, and stability of the network and the applications running on it

    • Add a note hereManaging and resolving problems affecting the system and keeping software applications current

Add a note here Design Methodology

Add a note hereWhen working in an environment that requires creative production on a tight schedule—for example, when designing an internetwork—using a methodology can be helpful. A methodology is a documented, systematic way of doing something.

Add a note hereFollowing a design methodology can have many advantages:

  • Add a note hereIt ensures that no step is missed when the process is followed.

  • Add a note hereIt provides a framework for the design process deliverables.

  • Add a note hereIt encourages consistency in the creative process, enabling network designers to set appropriate deadlines and maintain customer and manager satisfaction.

  • Add a note hereIt allows customers and managers to validate that the designers have thought about how to meet their requirements.

Add a note here The design methodology presented here includes three basic steps; some of the design methodology steps are intrinsic to the PPDIOO Design phase, whereas other steps are related to other PPDIOO phases:

Add a note here Step 1

Add a note here Identify customer requirements: In this step, which is typically completed during the PPDIOO Prepare phase, key decision makers identify the initial requirements. Based on these requirements, a high-level conceptual architecture is proposed.

Add a note here Step 2

Add a note here Characterize the existing network and sites: 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 operational environment can support the proposed system. Characterization of the existing network and sites includes site and network audit and network analysis. During the network audit, the existing network is thoroughly checked for integrity and quality. During the network analysis, network behavior (traffic, congestion, and so forth) is analyzed.

Add a note here Step 3

Add a note here Design the network topology and solutions: In this step, the detailed design of the network is created. Decisions are made about networked infrastructure, infrastructure services, and applications. The data for making these decisions is gathered during the first two steps.

Add a note hereA pilot or prototype network might be constructed to verify the correctness of the design and to identify and correct any problems as a proof of concept before implementing the entire network.

Add a note hereA detailed design document is also written during this step; it includes information that has been documented in the previous steps.

Add a note hereWhen the design is complete, the design implementation process is executed; this process includes the following steps:

Add a note here Step 1

Add a note here Plan the implementation: During this step, the implementation procedures are prepared in advance to expedite and clarify the actual implementation. Cost assessment is also undertaken at this time. This step is performed during the PPDIOO Design phase.

Add a note here Step 2

Add a note here Implement and verify the design: The actual implementation and verification of the design take place during this step by building a network. This step maps directly to the Implement phase of the PPDIOO methodology.


Note

Add a note hereA pilot or prototype network verifies the design somewhat; however, the design is not truly verified until it is actually implemented.

Add a note here Step 3

Add a note here Monitor and optionally redesign: The network is put into operation after it is built. During operation, the network is constantly monitored and checked for errors. If troubleshooting problems become too frequent or even impossible to manage, a network redesign might be required; this can be avoided if all previous steps have been completed properly. This step is, in fact, a part of the Operate and Optimize phases of the PPDIOO methodology.

Add a note hereThe remaining sections in this chapter detail each of the design methodology steps, followed by a brief discussion of the implementation process steps.

Identifying Customer Requirements

Add a note hereAs the organization’s network grows, so does the organization’s dependency on the network and the applications that use it. Network-accessible organizational data and mission-critical applications that are essential to the organization’s operations depend on network availability.

Add a note hereTo design a network that meets customers’ needs, the organizational goals, organizational constraints, technical goals, and technical constraints must be identified. This section describes the process of determining which applications and network services already exist and which ones are planned, along with associated organizational and technical goals and constraints. We begin by explaining how to assess the scope of the design project. After gathering all customer requirements, the designer must identify and obtain any missing information and reassess the scope of the design project to develop a comprehensive understanding of the customer’s needs.

Add a note here Assessing the Scope of a Network Design Project

Add a note hereWhen assessing the scope of a network design, consider the following:

  • Add a note hereWhether the design is for a new network or is a modification of an existing network.

  • Add a note hereWhether the design is for an entire enterprise network, a subset of the network, or a single segment or module. For example, the designer must ascertain whether the design is for a set of Campus LANs, a WAN, or a remote-access network.

  • Add a note hereWhether the design addresses a single function or the network’s entire functionality.

Add a note hereExamples of designs that would involve the entire network include one in which all branch office LANs are upgraded to support Fast Ethernet, and a migration from traditional Private Branch Exchange (PBX)–based telephony to an IP telephony solution. A project to reduce bottlenecks on a slow WAN is an example that would likely affect only the WAN. Adding wireless client mobility or provisioning core redundancy are designs that would likely affect only the campus.

Add a note here The Open Systems Interconnection (OSI) reference model is important during the design phase. The network designer should review the project scope from the protocol layer perspective and decide whether the design is needed for only the network layer, or if other layers are also involved. For example:

  • Add a note hereThe network layer includes the routing and addressing design.

  • Add a note hereThe application layer includes the design of application data transport (such as transporting voice).

  • Add a note hereThe physical and data link layers include decisions about the connection types and the technologies to be used, such as Gigabit Ethernet, Asynchronous Transfer Mode, and Frame Relay.


Note

Add a note here Appendix C, “Open System Interconnection (OSI) Reference Model,” details the seven layers of the OSI reference model.

Add a note here Table 2-1 exhibits sample results of assessing the scope of design for a sample enterprise, Corporation X.

Add a note here Table 2-1: Corporation X Network Design Scope Assessment
Open table as spreadsheet

Add a note hereScope of Design

Add a note hereComments

Add a note hereEntire network

Add a note hereThe backbone at the central office needs to be redesigned. All branch offices’ LANs will be upgraded to Fast Ethernet technology.

Add a note hereNetwork layer

Add a note hereIntroduction of private IP addresses requires a new addressing plan. Certain LANs must also be segmented. Routing must be redesigned to support the new addressing plan and to provide greater reliability and redundancy.

Add a note hereData link layer

Add a note hereThe central office backbone and some branch offices require redundant equipment and redundant links are needed. The organization also requires a campus wireless radio frequency (RF) site survey to determine mobility deployment options and equipment scope.

Add a note here Identifying Required Information

Add a note hereDetermining requirements includes extracting initial requirements from the customer and then refining these with other data that has been collected from the organization.

Extracting Initial Requirements

Add a note hereInitial design requirements are typically extracted from the Request for Proposal (RFP) or Request for Information (RFI) documents that the customer issues. An RFP is a formal request to vendors for proposals that meet the requirements that the document identifies. An RFI is typically a less formal document an organization issues to solicit ideas and information from vendors about a specific project.

Add a note hereThe first step in the design process should be predocumenting (sifting, processing, reordering, translating, and so forth) the design requirements and reviewing them with the customer for verification and approval, obtaining direct customer input, in either oral or written form. Figure 2-6 illustrates an iterative approach to developing the design requirements document.

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Add a note hereFigure 2-6: Iterative Approach to Identifying Customer Requirements

Add a note here Figure 2-6 illustrates the following steps:

Add a note here Step 1

Add a note hereExtract the initial customer requirements (from the RFP or RFI).

Add a note here Step 2

Add a note here Query the customer for a verbal description of the initial requirements.

Add a note here Step 3

Add a note hereProduce a draft document that describes the design requirements.

Add a note here Step 4

Add a note hereVerify the design requirements with the customer, and obtain customer approval.

Add a note here Step 5

Add a note here Revise the document as necessary to eliminate errors and omissions.

Add a note here Steps 2 to 5 are repeated if the customer has additional comments about the draft document.

Gathering Network Requirements

Add a note hereAs illustrated in Figure 2-7, the process of gathering requirements can be broken down into five steps. During these steps (which are sometimes called milestones), the designer discusses the project with the customer’s staff to determine and gather the necessary data, including appropriate documentation.

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Add a note hereFigure 2-7: Gathering Data for Design Requirements

Add a note hereAs shown in Figure 2-7, the steps are as follows:

Add a note here Step 1

Add a note hereIdentify the planned network applications and network services.

Add a note here Step 2

Add a note hereDetermine the organizational goals.

Add a note here Step 3

Add a note hereDetermine the possible organizational constraints.

Add a note here Step 4

Add a note hereDetermine the technical goals.

Add a note here Step 5

Add a note hereDetermine the technical constraints that must be taken into account.

Add a note hereThese steps provide the designer with data that must be carefully interpreted, analyzed, and presented to support the design proposal. Throughout these steps, the designer takes thorough notes, produces documentation, and presents the findings to the customer for further discussion.

Add a note here The process is not unidirectional; the designer might return to a step and make additional inquiries about issues as they arise during the design process. The next five sections detail these steps.

Add a note here Planned Applications and Network Services

Add a note hereThe designer must determine which applications the customer is planning to use and the importance of each of these applications. Using a table helps organize and categorize the applications and services planned; the table should contain the following information:

  • Add a note here Planned application types: Include e-mail, groupware (tools that aid group work), voice networking, web browsing, video on demand (VoD), databases, file sharing and transfer, computer-aided manufacturing, and so forth.

  • Add a note here Applications: Specific applications that will be used, such as Microsoft Internet Explorer, Cisco Unified MeetingPlace, and so forth.

  • Add a note here Level of importance: The importance of the applications—whether critical or important or not important—is noted.

  • Add a note here Comments: Additional notes taken during the data-gathering process.

Add a note here Table 2-2 shows an example of data gathered about the planned applications for the sample company, Corporation X.

Add a note here Table 2-2: Corporation X’s Planned Applications
Open table as spreadsheet

Add a note hereApplication Type

Add a note hereApplication

Add a note hereLevel of Importance (Critical, Important, Not Important)

Add a note hereComments

Add a note hereE-mail

Add a note hereMicrosoft Office Outlook

Add a note hereImportant

Add a note hereGroupware

Add a note hereCisco Unified MeetingPlace

Add a note hereImportant

Add a note hereNeed to be able to share presentations and applications during remote meetings

Add a note hereWeb browsing

Add a note hereMicrosoft Internet Explorer, Netscape Navigator, Opera

Add a note hereImportant

Add a note hereVideo on demand

Add a note hereCisco Digital Media System

Add a note hereCritical

Add a note hereDatabase

Add a note hereOracle

Add a note hereCritical

Add a note hereAll data storage is based on Oracle

Add a note hereCustomer support applications

Add a note hereCustom applications

Add a note hereCritical


Note

Add a note here The Cisco Digital Media System is an enhanced system that can be used in place of the Cisco Internet Protocol Television (IP/TV) products; Cisco has announced the end-of-sale and end-of-life dates for the Cisco IP/TV 3400 Series products. See http://www.cisco.com/en/US/netsol/ns620/networking_solutions_white_paper0900aecd80537d33.shtml for more details.


Note

Add a note hereInformation on the Opera browser is available at http://www.opera.com/.

Add a note hereThe planned infrastructure services table is similar to the planned application table. It lists infrastructure services that are planned for the network and additional comments about those services.

Add a note hereRecall that infrastructure services include security, QoS, network management, high availability, and IP multicast. Software distribution, backup, directory services, host naming, and user authentication and authorization are examples of other services and solutions that are deployed to support a typical organization’s many applications. Table 2-3 shows sample data that was gathered about the infrastructure services planned for the sample company, Corporation X.

Add a note here Table 2-3: Corporation X’s Planned Infrastructure Services
Open table as spreadsheet

Add a note hereService

Add a note hereComments

Add a note hereSecurity

Add a note hereDeploy security systematically: Firewall technology to protect the internal network; virus-scanning application to check incoming traffic for viruses; intrusion detection and prevention systems to protect from and inform about possible outside intrusions. Consider the use of authentication, authorization, and accounting systems to ensure that only authenticated and authorized users have access to specific services.

Add a note hereQoS

Add a note hereImplementation of QoS to prioritize more important and more delay-sensitive traffic over less important traffic (higher priority for voice and database traffic; lower priority for HTTP traffic).

Add a note hereNetwork management

Add a note hereIntroduction and installation of centralized network management tools (such as HP OpenView with CiscoWorks applications) for easier and more efficient network management.

Add a note hereHigh availability

Add a note hereUse redundant paths and terminate connections on different network devices to eliminate single points of failure.

Add a note hereIP multicast

Add a note hereIntroduction of IP multicast services needed for the introduction of videoconferencing and e-learning solutions.

Add a note hereVoice

Add a note hereCompany wants to migrate to IP telephony.

Add a note hereMobility

Add a note hereNeed mobility for employees and guest access for clients.

Add a note here Organizational Goals

Add a note here Every design project should begin by determining the organizational goals that are to be achieved. The criteria for success must be determined, and the consequences of a failure understood.

Add a note hereNetwork designers are often eager to start by analyzing the technical goals before considering the organizational goals and constraints. However, detailed attention to organizational goals and constraints is important for a project’s success. In discussions about organizational goals, the designer obtains knowledge about the customer’s expectations of the design’s positive outcomes for the organization. Both short- and long-term goals should be identified. This organization-centered approach allows the network to become a strategic asset and competitive weapon for the customer.

Add a note herePreliminary research on the organization’s activities, products, processes, services, market, suppliers, competitive advantages, and structure enhances the positioning of the technologies and products to be used in the network.

Add a note hereThis is an opportunity to determine what is important to the customer. Some sample questions a designer might ask to help determine organizational goals include the following:

  • Add a note hereWhat are you trying to accomplish with this project?

  • Add a note hereWhat business challenges are you currently facing?

  • Add a note hereWhat are the consequences of not resolving these issues?

  • Add a note hereHow would you measure or quantify success if you could fix or correct the identified problems and issues?

  • Add a note hereWhat applications are most critical to your organization?

  • Add a note hereWhat is the major objective of this project?

  • Add a note hereWhat is driving the change?

  • Add a note hereDo you need to support any government or safety or legal mandates?

  • Add a note hereWhat are your main concerns with the implementation of a new solution?

  • Add a note hereWhat technologies or services are needed to support your objectives?

  • Add a note here What other technology projects and business initiatives will affect your group in the next two to five years?

  • Add a note hereWhat skill sets does your technical staff currently have?

  • Add a note hereWhat is your goal for return on investment?

Add a note hereOrganizational goals differ from organization to organization. The following are some typical goals that commercial organizations might have:

  • Add a note hereIncrease the operation’s generated revenue and profitability. A new design should reduce costs in certain segments and propel growth in others. The network designer should discuss with the customer any expectations about how the new network will influence revenues and profits.

  • Add a note hereShorten development cycles and enhance productivity by improving internal data availability and interdepartmental communications.

  • Add a note hereImprove customer support and offer additional customer services that can expedite reaction to customer needs and improve customer satisfaction.

  • Add a note hereOpen the organization’s information infrastructure to all key stakeholders (prospects, investors, customers, partners, suppliers, and employees), and build relationships and information accessibility to a new level.


Note

Add a note hereSimilar, though not identical, goals are common to governmental, charitable, religious, and educational organizations. Most of these entities focus on using available resources effectively to attain the organization’s goals and objectives. In not-for-profit organizations, key measures are typically stated in terms of cost containment, service quality, service expansion, and resource deployment. This section emphasizes the deployment of networks in commercial organizations as an example of the type of research required for establishing the network requirements.

Add a note hereTo illustrate the importance of considering organizational goals in a network design, consider two manufacturing enterprises that are contemplating network updates. Enterprise A’s main reason for change is to improve customer satisfaction. It has received many complaints that customer information is difficult to obtain and understand, and there is a need for online ordering capability. In contrast, Enterprise B is driven by the need to reduce costs—this is a mandate from its CEO. When design decisions are made, these goals will most likely result in different outcomes. For example, Enterprise A might choose to implement an integrated product information database with e-commerce capability, whereas Enterprise B might not see the value of investing in this technology.

Add a note here Following are examples of the types of data that can be gathered about some common organizational goals:

  • Add a note here Increase competitiveness: List competitive organizations and their advantages and weaknesses. Note possible improvements that might increase competitiveness or effectiveness.

  • Add a note here Reduce costs: Reducing operational costs can result in increased profitability (even without a revenue increase) or increased services with the same revenue. List current expenses to help determine where costs could be reduced.

  • Add a note here Improve customer support: Customer support services help provide a competitive advantage. List current customer support services, with comments about possible and desired improvements.

  • Add a note here Add new customer services: List current customer services, and note future and desired (requested) services.

Add a note here Table 2-4 presents data gathered about the organizational goals of a sample company, Corporation X.

Add a note here Table 2-4: Corporation X’s Organizational Goals
Open table as spreadsheet

Add a note hereOrganizational Goal

Add a note hereGathered Data (Current Situation)

Add a note hereComments

Add a note hereIncrease competitiveness

Add a note hereCorporation Y

Add a note hereCorporation Z

Add a note hereBetter products

Add a note hereReduced costs

Add a note hereReduce cost

Add a note hereRepeating tasks—entering data multiple times, time-consuming tasks

Add a note hereSingle data-entry point

Add a note hereEasy-to-learn applications

Add a note hereSimple data exchange

Add a note hereImprove customer support

Add a note hereOrder tracking and technical support is done by individuals

Add a note hereIntroduction of web-based order tracking and web-based tools for customer technical support

Add a note hereAdd new customer services

Add a note hereCurrent services:

Add a note hereTelephone and fax orders, and telephone and fax confirmation

Add a note hereSecure web-based ordering

Add a note hereSecure web-based confirmations

Add a note here Organizational Constraints

Add a note here When assessing organizational goals, it is important to analyze any organizational constraints that might affect the network design. Some sample questions the designer might ask to help determine organizational constraints include the following:

  • Add a note hereWhat in your current processes works well?

  • Add a note hereWhat in your current processes does not work well?

  • Add a note hereWhich processes are labor-intensive?

  • Add a note hereWhat are the barriers for implementation in your organization?

  • Add a note hereWhat are your major concerns with the implementation of a new solution?

  • Add a note hereWhat financial and timing elements must be considered?

  • Add a note hereWhat projects already have budget approval?

  • Add a note hereAre other planned technology projects and business initiatives compatible with your current infrastructure and technology solutions?

  • Add a note hereWhat qualifications does your current staff have? Do you plan to hire more staff? If so, for what roles?

  • Add a note hereDo you have a budget for technical development for your staff?

  • Add a note hereAre there any policies in place that might affect the project?

Add a note hereTypical constraints include the following:

  • Add a note here Budget: Reduced budgets or limited resources often force network designers to implement an affordable solution rather than the best technical solution. This usually entails some compromises in availability, manageability, performance, and scalability. The budget must include all equipment purchases, software licenses, maintenance agreements, staff training, and so forth. Budget is often the final decision point for design elements, selected equipment, and so on. The designer must know how much money is available to invest in a solid design. It also useful to know the areas in which the network can be compromised to meet budget requirements.

  • Add a note here Personnel: The availability of trained personnel within the organization might be a design consideration. Organizations might not have enough trained personnel, or they might not have enough personnel. Familiarity with both the equipment and technologies speeds deployment and reduces cost, and trained technicians must be available to verify that all network elements are working. Therefore, the designer must know the number and availability of operations personnel, their expertise, and possible training requirements. Additional constraints might be imposed if the organization is outsourcing network management. The designer must consider the network’s implementation and maintenance phases, which require adequately trained staff.

  • Add a note here Policies: Organizations have different policies about protocols, standards, vendors, and applications; to design the network successfully, the designer must understand these policies. For example, the designer should determine customer policies related to single-vendor or multivendor platforms; an end-to-end single-vendor solution might be a benefit, because compatibility issues do not restrain the network. As another example, many organizations, such as government agencies (for example, defense departments), often have strict policies preventing implementation of proprietary protocols.

  • Add a note here Schedule: The organization’s executive management must discuss and approve the project schedule to avoid possible disagreements about deadlines. For example, the introduction of new network applications often drives the new network design; the implementation time frames for new applications are often tightly connected and therefore influence the available time for network design.

Add a note here Table 2-5 shows organizational constraints and accompanying data that has been collected for a sample company, Corporation X.

Add a note here Table 2-5: Corporation X’s Organizational Constraints
Open table as spreadsheet

Add a note hereOrganizational Constraint

Add a note hereGathered Data (Current Situation)

Add a note hereComments

Add a note hereBudget

Add a note here$650,000

Add a note hereBudget can be extended by a maximum of $78,000

Add a note herePersonnel

Add a note hereTwo engineers with college degrees and Cisco Certified Network Associate (CCNA) certifications for network maintenance; one has Cisco Certified Network Professional (CCNP) certification

Add a note hereThree engineers for various operating systems and applications maintenance

Add a note herePlans to hire additional engineers for network maintenance; need technical development plan for staff

Add a note herePolicy

Add a note herePrefers a single vendor and standardized protocols

Add a note hereCurrent equipment is Cisco; prefers to stay with Cisco

Add a note hereSchedule

Add a note herePlans to introduce various new applications in the next nine months

Add a note hereNew applications that will be introduced shortly are videoconferencing, groupware, and IP telephony

Add a note here Technical Goals

Add a note here The technical goals of the project must also be determined before the design starts. Some sample questions the designer might ask to help determine technical goals include the following:

  • Add a note hereWhat are your technology priorities?

  • Add a note hereHow does your technology budgeting process work?

  • Add a note hereWhat infrastructure issues exist or will exist related to your applications rollouts?

  • Add a note hereWhat skill sets does your technical staff need to acquire?

  • Add a note hereDoes your current network have any performance issues?

  • Add a note hereWhich portions of your network are considered mission-critical?

  • Add a note hereDo you anticipate significant growth in the number of network users over the next few years?

  • Add a note hereHow is your network managed now?

Add a note hereThe following list describes some common technical goals:

  • Add a note here Improve network performance: An increase in the number of users and the introduction of new applications might degrade network performance, especially responsiveness and throughput. The first goal of network redesign is usually to increase performance—for example, by upgrading the speed of links or by partitioning the network into smaller segments.


    Note

    Add a note here Performance is a general term that includes responsiveness, throughput, and resource utilization. The users of networked applications and their managers are usually most sensitive to responsiveness issues; speed is of the essence. The network system’s managers often look to throughput as a measure of effectiveness in meeting the organization’s needs. Executives who have capital budget responsibility tend to evaluate resource utilization as a measure of economic efficiency. It is important to consider the audience when presenting performance information.

  • Add a note here Improve security and reliability of mission-critical applications and data: Increased threats from both inside and outside the enterprise network require the most up-to-date security rules and technologies to avoid disruptions of network operation.

  • Add a note here Decrease expected downtime and related expenses: When a network failure occurs, downtime must be minimal, and the network must respond quickly to minimize related costs.

  • Add a note here Modernize outdated technologies: The emergence of new network technologies and applications demands regular updates to and replacement of outdated equipment and technologies.

  • Add a note here Improve scalability of the network: Networks must be designed to provide for upgrades and future growth.

  • Add a note here Simplify network management: Simplify network management functions so that they are easy to use and easily understood.

Add a note hereUsing a table helps the designer identify technical goals. Different goals have different levels of importance, which the customer should determine. One way of expressing the level of importance is with percentages: Specific technical goals are rated in importance on a scale from 1 to 100, with the sum totaling 100; this scale provides direction for the designer when choosing equipment, protocols, features, and so forth.

Add a note here Table 2-6 depicts the desired technical goals that were gathered for the sample company, Corporation X, along with their importance rating and additional comments. In this example, the designer sees that the customer places great importance on availability, scalability, and performance; this suggests that the network design should include redundant equipment, redundant paths, use of high-speed links, and so forth.

Add a note here Table 2-6: Corporation X’s Technical Goals
Open table as spreadsheet

Add a note hereTechnical Goals

Add a note hereImportance

Add a note hereComments

Add a note herePerformance

Add a note here20

Add a note hereImportant in the central site, less important in branch offices

Add a note hereSecurity

Add a note here15

Add a note hereThe critical data transactions must be secure

Add a note hereAvailability

Add a note here25

Add a note hereShould be 99.9%

Add a note hereAdaptability (to new technologies)

Add a note here10

Add a note hereScalability

Add a note here25

Add a note hereThe network must be scalable

Add a note hereManageability

Add a note here5

Add a note hereTotal 100

Add a note here Technical Constraints

Add a note hereNetwork designers might face various technical constraints during the design process. Some sample questions the designer might ask to help determine technical constraints include the following:

  • Add a note hereHow do you determine your technology priorities?

  • Add a note hereDo you have a technology refresh process? If so, is that an obstacle, or does it support the proposed project?

  • Add a note here What urgent technical problems require immediate resolution or mitigation?

  • Add a note hereDo you have a plan for technical development for your staff in specific areas?

  • Add a note hereDo any applications require special network features (protocols and so forth)?

Add a note hereGood network design addresses constraints by identifying possible trade-offs, such as the following:

  • Add a note here Existing equipment: The network design process is usually progressive; legacy equipment must coexist with new equipment.

  • Add a note here Bandwidth availability: Insufficient bandwidth in parts of the network where the bandwidth cannot be increased because of technical constraints must be resolved by other means.

  • Add a note here Application compatibility: If the new network is not being introduced at the same time as new applications, the design must provide compatibility with old applications.

  • Add a note here Lack of qualified personnel: Lack of qualified personnel suggests that the designer must consider the need for additional training; otherwise, certain features might have to be dropped. For example, if the network proposal includes the use of IP telephony but the network administrators are not proficient in IP telephony, it might be necessary to propose an alternative solution.

Add a note hereUsing a table can facilitate the process of gathering technical constraints. The designer identifies the technical constraints and notes the current situation and the necessary changes that are required to mitigate a certain constraint.

Add a note here Table 2-7 presents sample technical constraints gathered for Corporation X. Under existing equipment, the designer notes that the coaxial cabling in the LAN’s physical cabling plant still exists and comments that twisted pair and fiber optics should replace it. The bandwidth availability indicates that the WAN service provider does not have any other available links; the organization should consider changing to another service provider. Application compatibility suggests that the designer should take care when choosing equipment.

Add a note here Table 2-7: Technical Constraints for Corporation X
Open table as spreadsheet

Add a note hereTechnical Constraints

Add a note hereGathered Data (Current Situation)

Add a note hereComments

Add a note hereExisting equipment

Add a note hereCoaxial cable

Add a note hereThe cabling must be replaced with twisted pair to the desktop, and fiber optics for uplinks and in the core

Add a note hereBandwidth availability

Add a note here64-kbps WAN link

Add a note hereUpgrade bandwidth; change to another service provider because the current one does not have any other links to offer

Add a note hereApplication compatibility

Add a note hereIP version 6 (IPv6)-based applications

Add a note hereNew network equipment must support IPv6


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