NETWORK DESIGN CHAPTER 1(1).pptx
- 1. CHAPTER1 APPLYING A METHODOLOGY TO NETWORK DESIGN 1 COMPILED BY TIZITA OBSSA Network Design chapter 1
- 2. CONTENTS OVERVIEW (what is computer network? its advantage & dis advantage) Introduction Discovering Network Design Basics. Network Design Overview. Network Requirements. Building a Good Network. Fundamental NETWORK Design Goals Benefits of a Hierarchical Network Design Benefits of a Hierarchical Network Design ADVANTANTAGES OF HIERARCHICAL NETWORK 2 COMPILED BY TIZITA OBSSA Network Design chapter 1
- 3. INTRODCTION Network designers ensure that our communications networks can adjust and scale to the demands for new services. To support our network-based economy, designers must work to create networks that are available nearly 100 percent of the time. Information network security must be designed to automatically fend off unexpected security incidents. Using hierarchical network design principles and an organized design methodology, designers create networks that are both manageable and supportable. 3 COMPILED BY TIZITA OBSSA Network Design chapter 1
- 4. Discovering Network Design Basics The sections that follow cover the basics of network design with regard to the following concepts: ■ Network design overview ■ The benefits of a hierarchical network design ■ Network design methodology 4 COMPILED BY TIZITA OBSSA Network Design chapter 1
- 5. Network Design Overview Computers and information networks are critical to the success of businesses, both large and small. They connect people, support applications and services, and provide access to the resources that keep the businesses running. To meet the daily requirements of businesses, networks themselves are becoming quite complex 5 COMPILED BY TIZITA OBSSA Network Design chapter 1
- 6. Network Requirements Today, the Internet-based economy often demands around-the- clock customer service. This means that business networks must be available nearly 100 percent of the time. They must be smart enough to automatically protect against unexpected security incidents. These business networks must also be able to adjust to changing traffic loads to maintain consistent application response times. It is no longer practical to construct networks by connecting many standalone components without careful planning and design. 6 COMPILED BY TIZITA OBSSA Network Design chapter 1
- 7. Building a Good Network Building a good network do not happen by accident. They are result of hard work by network designers and technicians, who identify network requirements and select the best solutions to meet the needs of a business. 7 COMPILED BY TIZITA OBSSA Network Design chapter 1
- 8. STEPS REQUIRED TO DESIGN A GOOD NETWORK The steps required to design a good network are as follows: Step 1. Verify the business goals and technical requirements.(HOW?) Step 2. Perform a network-readiness assessment (HOW?) Step 3. Create a solution and site acceptance test plan. (HOW?) Step 4. Create a project plan. (HOW?) Step 5. Determine the features and functions required to meet the needs identified in Step 1. (HOW?) 8 COMPILED BY TIZITA OBSSA Network Design chapter 1
- 9. After the network requirements have been identified, the steps to designing a good network are followed as the project implementation moves forward. Network users generally do not think in terms of the complexity of the underlying network. They think of the network as a way to access the applications they need, when they need them. 9 COMPILED BY TIZITA OBSSA Network Design chapter 1
- 10. Network Requirements Most businesses actually have only a few requirements for their network: The network should stay up all time, even in event of failed links, equipment failure, and overloaded conditions. The network should reliably deliver applications and provide reasonable response times from any host to any host. The network should be secure. It should protect the data that is transmitted over it and data stored on the devices that connect to it. 10 COMPILED BY TIZITA OBSSA Network Design chapter 1
- 11. CONT… The network should be easy to modify to adapt to network growth and general business changes. Because failures occasionally occur, trouble shooting should be easy. Finding and fixing a problem should not be too time- consuming 11 COMPILED BY TIZITA OBSSA Network Design chapter 1
- 12. FUNDAMENTAL NETWORK DESIGN GOALS When examined carefully, these requirements translate into four fundamental network design goals: ■ Scalability: Scalable network designs can grow to include new user groups and remote sites and can support new applications without impacting the level of service delivered to existing users. ■ Availability: A network designed for availability is one that delivers consistent, reliable performance, 24 hours a day, 7 days a week. In addition, the failure of a single link or piece of equipment should not significantly impact network performance. 12 COMPILED BY TIZITA OBSSA Network Design chapter 1
- 13. CONT… Security: Security is a feature that must be designed into the network, not added on after the network is complete. Planning the location of security devices, filters, and firewall features is critical to safeguarding network resources. ■ Manageability: No matter how good the initial network design is, the available network staff must be able to manage and support the network. A network that is too complex or difficult to maintain cannot function effectively and efficiently 13 COMPILED BY TIZITA OBSSA Network Design chapter 1
- 14. BENEFITS OF A HIERARCHICAL NETWORK DESIGN The Benefits of a Hierarchical Network Design To meet the four fundamental design goals, a network must be built on an architecture that allows for both flexibility and growth. 14 COMPILED BY TIZITA OBSSA Network Design chapter 1
- 15. CONT… Hierarchical Network Design In networking, a hierarchical design is used to group devices into multiple networks. The networks are organized in a layered approach. The hierarchical design model has three basic layers: Core layer: Connects distribution layer devices. Distribution layer: Interconnects the smaller local networks. Access layer: Provides connectivity for network hosts and end devices . 15 COMPILED BY TIZITA OBSSA Network Design chapter 1
- 16. ADVANTANTAGES OF HIERARCHICAL NETWORK Hierarchical networks have advantages over flat network designs. The benefit of dividing a flat network into smaller, more manageable hierarchical blocks is that local traffic remains local. Only traffic destined for other networks is moved to a higher layer. 16 COMPILED BY TIZITA OBSSA Network Design chapter 1
- 17. CONT… Layer 2 devices in a flat network provide little opportunity to control broadcasts or to filter undesirable traffic. As more devices and applications are added to a flat network, response times degrade until the network becomes unusable. Figures 1-1 and 1-2 show the advantages of a hierarchical network design versus a flat network design. 17 COMPILED BY TIZITA OBSSA Network Design chapter 1
- 18. FIGURE 1-1 FLAT NETWORK 18 COMPILED BY TIZITA OBSSA Network Design chapter 1