© 2007 Cisco Systems, Inc. All rights reserved.DESGN v Applying a Methodology to Network Design Identifying Design Requirements

© 2007 Cisco Systems, Inc. All rights reserved.DESGN v PPDIOO Network Life-Cycle Approach

© 2007 Cisco Systems, Inc. All rights reserved.DESGN v Benefits of the Life-Cycle Approach

© 2007 Cisco Systems, Inc. All rights reserved.DESGN v Design Methodology Under PPDIOO Three steps in the design methodology: 1. Identify the customer requirements. 2. Characterize the existing network and sites. 3. Design the topology and network solutions.

© 2007 Cisco Systems, Inc. All rights reserved.DESGN v Identifying Customer Requirements

© 2007 Cisco Systems, Inc. All rights reserved.DESGN v Identifying Planned Applications Application TypeApplication Criticality (Critical/Important/ Unimportant) Comments Groupware Web browsing Video on demand Database Customer support

© 2007 Cisco Systems, Inc. All rights reserved.DESGN v Example: Planned Applications Application TypeApplication Criticality (critical/important/ unimportant) Comments Microsoft OutlookImportant Groupware Cisco Unified MeetingPlace Important We need to be able to share presentations and applications during remote meetings. Web browsing Microsoft Internet Explorer, Opera, Netscape Important Video on demandIP/TVCritical DatabaseOracleCritical All data storage will be based on Oracle. Customer support Customer applications Critical

© 2007 Cisco Systems, Inc. All rights reserved.DESGN v Identifying Planned Infrastructure Services ServiceComments Security QoS Network management High availability IP telephony Mobility

© 2007 Cisco Systems, Inc. All rights reserved.DESGN v Example: Planned Infrastructure Services ServiceComments Security Deploy security systematically, including firewalls, intrusion detection systems (IOSs), and access control lists (ACLs) QoSGive priority to delay-sensitive voice traffic and other important traffic Network management Use centralized management tools where appropriate and point product management as required High availabilityEliminate single points of failure and use redundant paths as needed IP telephonyWant to migrate company from regular telephony MobilityNeed client laptop guest access along with mobility of employee PCs

© 2007 Cisco Systems, Inc. All rights reserved.DESGN v Identifying Organizational Goals Organizational GoalGathered DataComments Increase competitiveness List competitive organizations and their abilities Point out possibilities to increase competitiveness Reduce costsList current expenses Point out cost-reduction possibilities Improve customer supportList current customer support Point out possible steps to improve customer support Add new customer servicesList current customer servicesList future desired services

© 2007 Cisco Systems, Inc. All rights reserved.DESGN v Example: Organizational Goals Organizational Goal Gathered Data (Existing Situation) Comments Increase competitivenessCorporation Y, Corporation Z Better products Reduce costs Enter data multiple times; time-consuming tasks Single data-entry point Easy-to-learn application Simple data exchange Improve customer support Order tracking and technical support supported by individuals Web-based order tracking Web-based customer technical support tools Add new customer services Telephone and fax orders; telephone and fax confirmation Secure web-based ordering Secure web-based confirmations

© 2007 Cisco Systems, Inc. All rights reserved.DESGN v Assessing Organizational Constraints Organizational ConstraintGathered DataComments BudgetAmount of money to spend Identify the amount of money the organization is willing to spend Personnel List available personnel and their expertise Specify the number of network engineers who have to attend the additional training Policy List preferred standards, protocols, vendors, applications Determine if the organization is willing to buy equipment from new vendor SchedulingSpecify time frame Use tools for resource assignment, milestones, critical- path analysis

© 2007 Cisco Systems, Inc. All rights reserved.DESGN v Example: Organizational Constraints Organizational Constraint Gathered Data (Existing Situation) Comments Budget$650,000 Budget can be extended by maximum $78,000 Personnel Engineers with Cisco CCNA ® certificates and Cisco CCNP ® certificates Plans to hire new engineers in the network department; need technical development plan Policy Prefers single vendor and standardized protocols Current equipmentCisco; prefers to stay with it Scheduling Plans to introduce new applications in the next nine months New applications include video conferencing, groupware, and IP telephony

© 2007 Cisco Systems, Inc. All rights reserved.DESGN v Identifying Technical Goals Technical GoalsImportanceComments Responsiveness and throughput Availability Manageability Security Adaptability Scalability Total100

© 2007 Cisco Systems, Inc. All rights reserved.DESGN v Example: Technical Goals Technical GoalsImportanceComments Performance20 Important of the central site, less important in branch offices Availability25 Should be 99.9 percent Manageability5 Security15 Security for critical data transactions is extremely important Adaptability10 Scalability25 Scalability is critical Total100

© 2007 Cisco Systems, Inc. All rights reserved.DESGN v Example: Technical Constraints Technical ConstraintsGathered DataComments Existing wiringCoaxial cabling Replace existing coaxial cabling. Use twisted-pair to desktop and fiber optics for uplinks and in the backbone. Bandwidth availability64-kbps WAN links Upgrade speeds; consider another service provider with additional services to offer. Application compatibilityIPv6 based applications Make sure new network equipment supports IPv6.

© 2007 Cisco Systems, Inc. All rights reserved.DESGN v Summary The PPDIOO approach reflects the life cycle phases of a standard network. The design methodology under PPDIOO includes these processes: –Identifying customer requirements –Characterizing the existing network and sites –Designing the network topology and solutions Key steps in identifying customer requirements include these: –Identifying network applications and services –Defining organizational goals and constraints –Defining technical goals and constraints

© 2007 Cisco Systems, Inc. All rights reserved.DESGN v