1. Lecture6 Network Replacement
CH3: Working at a Small-to-Medium Business or ISP, CCNA Discovery Learning Guide
Power Point Slides: By Maysoon AlDuwais

2. Outline
Why is proper planning necessary when you perform a network upgrade?
What is a site survey, and why is it necessary?
What steps are involved in performing a site survey?
What is structured cabling?
What factors must you consider when upgrading LAN and internetworking devices?

3. Why We Need Replacement?
As businesses grow and evolve, they may outgrow their existing network and require upgrade.
To help ensure a smooth transition, look at the current network and the new network requirements.
the new network should supports both the current and future needs of the organization

4. Common Issues
When a small company grows, the original network cannot keep track with the expansion.
Employees may not realize that it is time for upgrade.
In many cases, the business connects new users and solve this problem by the fast solution:
Adding various network hardware
Devices of varying quality
Different manufacturers
Different connection technologies

5. Fast solution disadvantages
Cause a degradation in network quality as each new user or device is added.
the network may became unable to support the types and level of network traffic.
The network may fail.

6. Contacting an Expert
When the network starts to fail, businesses look for help to redesign the network.
An ISP may be called to provide advice and install and maintain the network upgrade.
Before a network upgrade can be properly designed
A technician is consulted to perform a site survey to evaluate the current network structure.

7. What is Site Survey?
It is a survey conducted to evaluate, investigate, & document the physical layout of the existing network to determine where new equipment can be installed and requirements for future growth.
It helps the network designer by giving him an evaluation of the current network and its status and requirements by gathering information from different people.

8. Site Survey Content
It may include all or some of the following information:
Number of users & type of equipment
Projected growth
Current Internet connectivity
Application Requirement
Existing network infrastructure
New services required
Security and privacy considerations
Wireless requirements
Reliability and uptime expectation
Budget constraints

9. Physical and Logical Topologies
Both the physical and logical topologies of the existing network need to be documented.
A technician gathers the information during the site survey to create both a physical and logical topology map of the network
Physical topology: is the actual physical location of cables, computers, and other peripherals.
Logical topology: documents the path that data takes through a network and the location where network functions

12. Network Requirements Documentation
This information helps the network designer determine what new equipment is required and the best way to structure the network it is written in an inventory sheet.
The inventory sheet includes the following:
Device name
Operating system
Date of purchase
Logical addressing information
Warranty information
Connection information
Location
Security information
Brand and model

13. Planning the Network Upgrade
Requirement is first identified, and then a plan outlines the upgrade process from beginning to end.
A good project plan helps identifying strengths, weaknesses, opportunities, & threats. (SWOT analysis).
The plan should clearly define the tasks and the order in which tasks are completed.

14. Network Upgrades
The planning of a network upgrade begins after the initial site survey and report are complete.
It consists of five distinct phases:
Phase 1: Requirements gathering
Phase 2: Selection and design
Phase 3: Implementation
Phase 4: Operation
Phase 5: Review and evaluation

15. Phase 1: Requirements Gathering
The ISP team:
Gather information from the customer and the site
analyzes the information to determine network requirements
generates an analysis report.

16. Phase 2: Selection and Design
When the analysis report is complete, devices and cabling are selected.
The design team creates multiple designs and shares them with team.
This allows team members to view LAN from a documentation perspective and evaluate options in performance and cost.
Any weaknesses of the design can be identified and addressed.
Prototypes are created and tested.
A successful prototype is a good indicator of how the new network will operate.

17. Phase 3: Implementation
If the first two phases are done correctly
The implementation phase may be performed without problems.
If tasks were missed in earlier phases, they must be corrected here.
A good implementation schedule must:
allow time for unexpected events
Schedules events to keep disruption of the customer’s business to a minimum.
Staying in contact with the customer during the installation is critical to the project’s success.

18. Phase 4: Operation
After implementation, the network moves to a production environment.
In this environment, the network is considered live and performs all the tasks it has been designed to accomplish.
If all steps up to this point have been properly completed, very few unexpected incidents should occur.

19. Phase 5: Review and Evaluation
At this phase, design & implementation must be reviewed & evaluated against original design objectives.
This is done by the design team with assistance from network staff.
Evaluation includes: costs, performance, & suitability for the environment.
Recommendations:
Compare the user experience with the goals in the documentation, and evaluate whether the design is right for the job.
Compare the projected designs and costs with the actual deployment.
Monitor the operation, and record changes.

20. Physical Environment
Before selecting equipment & determining the design of the new network, the network designer examines the existing network facilities & cabling in the site survey step.
The facilities include the physical environment, telecommunication room, & existing network wiring.
Main Distribution Facility (MDF)
A telecommunications room or wiring closet in a small, single-floor network.

22. MDF & IDF MDF contains network devices in single point, such as:
switches or hubs, routers, access points..etc.
network cable.
ISP’s point of presence (POP)
where the network connects to Internet through a telecommunications service provider.
If additional wiring closets are required, these are called intermediate distribution facilities (IDF).
IDFs are smaller than MD.F and connect to the MDF with backbone cabling

24. Purchasing and Maintaining Equipment
As ISP team plans network upgrade, issues to purche new equipment & maintaining new & existing equipment.
There are two options for new equipment:
managed service
The equipment is obtained from ISP through a lease or other agreement.
ISP is responsible for updating and maintaining equipment.
In-house solutions
Customer purchases the equipment
Customer is responsible for updates, warranties, & maintaining equipment.

25. Managed Service Vs. In-house Solution
Factor
Initial evaluation & choice of service provider
Requirements definition
Ongoing evaluation of service provider
Requires many decisions:
Type of equipment
Equipment location
IT organization staffing
Network design
Maintenance requirements
Considerations
Single, predictable, monthly bill
Minimal up-front costs
Equipment purchasing or leasing
Training costs
Multiple vendor costs and building
Hardware repairs and upgrades
Software release upgrades
Telephone line changes
Redundancy & reliability requirements
Cost

26. Managed Service Vs. In-house Solution
Factor
Delegate network management to a qualified ISP
Maintain control of work flow in your organization
Set service-level agreements (SLA) with ISP
You have most of the control and responsibility for managing and maintaining your network.
Control & Responsibility
ISP guarantee network availability up to 99%
A 24-hour help desk is available
ISP management is transparent to end users
You are responsible for keeping employees, customers, and
Reliability
Users are unaware of whether the network is managed by company or an external partner
Users are unaware of whether network is managed by the company or an external partner
End-User Experience

27. Selecting Network Devices: Selecting LAN Devices
When selecting a switch for a particular LAN, network designers must consider the following:
Speed and types of ports/interfaces
Expandability
Manageability
Cost

28. Selecting Network Devices: Selecting Internetworking Devices
You must consider number of factors for selecting a router.
It is necessary to match the router’s characteristics to network requirements.
Factors for choosing a router include:
The type of connectivity required
Features
Security
Quality of service (QoS)
Voice over IP (VoIP)
Network Address Translation (NAT)
Dynamic Host Configuration Protocol (DHCP)
Wireless access
Virtual private network (VPN)
Intrusion detection
Cost

29. Reliability and Availability
Reliability is achieved by adding redundant components to network, such as two routers instead of one.
Redundancy creates alternative paths, so if one router have problems, data can take alternative path to destination.
Complete redundancy for all devices & connections gives best reliability but it is expensive.
Design team determine redundancy level to achieve the necessary reliability.

31. Availability
Availability is the amount of time the network is ready and able to deliver the necessary services.
To improve availability improve the following:
reliability
Redundancy
Equipment and software that have been engineered to provide this level of service.
As example of availability, telephone systems require % of uptime.
Telephone systems cannot be down, or unavailable, more than .001%

32. Fault tolerance
Fault tolerance systems typically are used to improve network reliability.
When one device fails, the redundant or backup system takes over to ensure minimal loss of reliability

33. IP Addressing Plan
Planning for the network installation must include planning the logical addressing.
If the network’s structure is changed in the upgrade, the IP address scheme and network information may need to be altered to reflect the new structure.