Institute of Technology Sligo - Dept of Computing Chapter 8 Network Design and Documentation

Institute of Technology Sligo - Dept of Computing In previous chapters you learned : OSI model and data encapsulation process. Different LAN technologies. Layers 1 & 2 concepts and technologies. In this chapter you will start learning network design and documentation

Institute of Technology Sligo - Dept of Computing GENERAL DESIGN PROCESS  Network design takes into consideration the following LAN technologies: Token-Ring FDDI Ethernet (focus of the curriculum)

Institute of Technology Sligo - Dept of Computing Ethernet has - logical bus topology which leads to: Collision domains; - Your responsibility is to minimize them by: segmentation Once you have chosen Ethernet technology you must develop:

Institute of Technology Sligo - Dept of Computing  Step 1: Layer 1 topology: - Type of cable (most common is CAT 5) - Physical topology (extended star) - You may need to use hubs, repeaters, transceivers and other layer 1 components - Which type of Ethernet to be used: 10Base-T or 100Base-TX Layer 1 design finished with physical & logical topologies designed.

Institute of Technology Sligo - Dept of Computing  Step 2: Layer 2 design: -implementation of switches to reduce collision domain size. - VLAN design (sem- 3). -replacing hubs with switches for existing devices.

Institute of Technology Sligo - Dept of Computing  Step 3: Layer 3 design: - layer three devices (routers) to access WAN services & internet. - or you may need routers to segment broadcast domains & to add more security between different network segments.

Institute of Technology Sligo - Dept of Computing Network design issues First step in the design process is - to gather information about the organization: - Users requirements - types of applications - projected growth - operating policies & procedures - people who will be using the network

Institute of Technology Sligo - Dept of Computing Second step - Detailed analysis of gathered data: For example: * Based on user requirements, numbers of users, and applications types you can determine: - type of H/W : hubs, switches, vlans; * Based on projected growth, you may determine the scalability of your network : - number of switches in MDF and/or IDF - types of horizontal & backbone cabling - bandwidth per user : 10, 100 MBS;

Institute of Technology Sligo - Dept of Computing - Number and speed of ports per switch / hub - number and speed of ports to be used for backbone interconnections * Based on type of applications you may determine: - to divide users into groups in order to implement VLANs - placement of servers: - bandwidth per each user/group of users. some applications are accessed by all users (DNS, E- Mail,…..), other applications are specific (financial, video training,…)

Institute of Technology Sligo - Dept of Computing Third step - identify resources & constraints of the organization: - existing computer H/W - existing S/W resources - human resources - organization’s budget

Institute of Technology Sligo - Dept of Computing  Engineering journal.  Logical topology.  Physical topology.  Cut sheets.  Problem-solving matrices.  Labeled outlets.  Labeled cable runs.  Summary of outlets and cable runs.  Summary of devices, addresses. - During your network design you will create the following documents:

Institute of Technology Sligo - Dept of Computing

Planning structured cabling: wiring closet specifications

Institute of Technology Sligo - Dept of Computing Overview of wiring closet - Selection of wiring closets (MDF/ IDF) according to standards. One of the early decisions is: - MDF is where many of networking devices and cables will be installed

Institute of Technology Sligo - Dept of Computing Cabling standards

Institute of Technology Sligo - Dept of Computing Services as a central point of a star topology (TIA/EIA 568A standard) Services as a central point of a star topology (TIA/EIA 568A standard) Where the horizontal cabling runs must be attached Where the horizontal cabling runs must be attached Where the patch panels and switches/ hubs must be installed. Where the patch panels and switches/ hubs must be installed. Wiring closet specifications: Must be large enough to accommodate equipment and extra space for future growth: Must be large enough to accommodate equipment and extra space for future growth:

Institute of Technology Sligo - Dept of Computing

Each floor must have at least one wiring closetEach floor must have at least one wiring closet One wiring closet should be added for each 1000 or the horizontal cable distance exceeds 90m.One wiring closet should be added for each 1000 m 2 or the horizontal cable distance exceeds 90m..

Institute of Technology Sligo - Dept of Computing Environmental specifications  Materials for walls, floors, and ceilings.  Temperature and humidity.  Locations and types of lighting.  Power outlets.  Room and equipment access.  Cable access and support. Selected room/ closet should satisfy certain requirements for:

Institute of Technology Sligo - Dept of Computing 20mm plywood that is at least 2.4m Minimum load capacity. Raised floor or Ladder Rack Support. Tiled, or some other type of finished surface. Rooms must not have a dropped, or false, ceiling Walls, floors and ceiling

Institute of Technology Sligo - Dept of Computing - Temperature: 21 o. - humidity: 30 – 50%. VHAC Lighting and power outlets: - No water or steam pipes running through or above the room. - minimum of two dedicated, non - switched, AC duplex electrical outlets.

Institute of Technology Sligo - Dept of Computing - At least one duplex power outlet positioned every 1.8 m along each wall.. - power outlet should be positioned 150 mm above the floor. - main lighting control switch should be placed immediately inside the door - florescent lighting should be avoided for cable pathways.

Institute of Technology Sligo - Dept of Computing Room and equipment access: - door should be at least 0.9 m wide; - door should open out of the room; - switches/ hubs and patch panel may be mounted: - to wall using hinged wall bracket; - with distribution rack;

Institute of Technology Sligo - Dept of Computing

Wiring hub and patch panel were mounted to a wall with a hinged wall bracket. Wiring hub and patch panel were mounted with distribution rack

Institute of Technology Sligo - Dept of Computing

- All horizontal cabling that runs from work areas to a wiring closet should be run under a raised floor ; - When this is not possible, the cabling should be run through 10.2 cm sleeves that are placed above door level. - any wall/ ceiling openings should be sealed with a smoke and flame-retardant materials

Institute of Technology Sligo - Dept of Computing Wiring closet identification

Institute of Technology Sligo - Dept of Computing - You may think of a hub as a central point of a circle which has horizontal cables radiating from it.

Institute of Technology Sligo - Dept of Computing In order to determine the location of wiring closet begin by drawing the floor plan; In order to determine the location of wiring closet begin by drawing the floor plan; Add devices that will be connected to network;Add devices that will be connected to network; identify secure locations to be used as MDF/IDF; identify secure locations to be used as MDF/IDF; MDF should be close to the POP; MDF should be close to the POP; determine number of wiring closets; determine number of wiring closets;

Institute of Technology Sligo - Dept of Computing

draw circles of radius 50 m from each potential wiring closet (hub location) draw circles of radius 50 m from each potential wiring closet (hub location) if there are any potential wiring closets whose catchments areas substantially overlap, you may eliminate one of them. if there are any potential wiring closets whose catchments areas substantially overlap, you may eliminate one of them. if the catchment area does not cover all devices, repeaters are used (IDF). if the catchment area does not cover all devices, repeaters are used (IDF).

Institute of Technology Sligo - Dept of Computing

MDF location in multi-story building MDF is located on one of the middle floors, even though the POP might be located on the first floor.

Institute of Technology Sligo - Dept of Computing MDF location in multi-building campus

Institute of Technology Sligo - Dept of Computing Backbone cabling consists of: Backbone cabling runs Intermediate and main cross-connects. Vertical media between wiring closets on different floors. networking media between MDF and POP. Networking media used between buildings in multi-building campus. Patch cords used for backbone – to –backbone cross – connection:.

Institute of Technology Sligo - Dept of Computing

Backbone cabling media  UTP (four – pair). According to TIA/EIA 568 A, four type of networking media can be Used for backbone cabling:  STP (two – pair). - multimode optical fiber - single mode optical fiber.

Institute of Technology Sligo - Dept of Computing IDF can be connected to MDF in two ways:IDF can be connected to MDF in two ways: 1. IDF can be connected directly to MDF

Institute of Technology Sligo - Dept of Computing 2. 1 st IDF connected to 2 nd IDF; the 2 nd is then connected to MDF;

Institute of Technology Sligo - Dept of Computing No work areas are connected to ICC; No more than one ICC can be passed through to reach MDF

Institute of Technology Sligo - Dept of Computing Maximum distance for backbone cabling:Maximum distance for backbone cabling:

Institute of Technology Sligo - Dept of Computing

Electricity and Grounding

Institute of Technology Sligo - Dept of Computing DC current flows in a constant value Examples: flashlight, car battery, computer motherboard

Institute of Technology Sligo - Dept of Computing

AC noise all around us: in walls, ceilings, floors AC noise can come from: - from video monitors, H/D drives AC noise:AC noise:

Institute of Technology Sligo - Dept of Computing Electrostatic static discharge (ESD)Electrostatic static discharge (ESD) Static electricity: stationary electrons. Most damaging and uncontrollable Form of electricity. ESD destroy semiconductors and data. A solution that can help solve ESD problem: good grounding.

Institute of Technology Sligo - Dept of Computing Safety groundSafety ground

Institute of Technology Sligo - Dept of Computing Safety ground wire is connecting to any exposed metal of the equipment Motherboards and computing circuits in computers are connected to chassis this connects them to safety ground. Safety ground prevents metal parts from becoming energized. It serves as a low resistance path to the earth when a faulty connection between a hot line and chassis occurs.

Institute of Technology Sligo - Dept of Computing Multi-ground connectionsMulti-ground connections Large buildings frequently require more than one earth ground. Separate earth grounds also required in multi-building campus. Earth grounds between buildings is almost never the same. Also separate earth grounds for the same building may vary.

Institute of Technology Sligo - Dept of Computing When separate ground wires have different potential (voltage) to the common and hot wires they can present a serious problem If a circuit is established between devices in two buildings, then a current Would flow from negative to positive Source Such circuit could cause a nasty shock, and it may damage memory chips.

Institute of Technology Sligo - Dept of Computing

A good way to avoid current pass through the body, and through the heart, is to use one hand rule. Avoiding dangerous circuits between buildingsAvoiding dangerous circuits between buildings TIA/EIA standards recommends the use of optical fiber for backbone connections (between buildings, and between different floors within the same building. Optical fiber is a good insulator: Electricity does not travel over fiber.

Institute of Technology Sligo - Dept of Computing Network power supply issues

Institute of Technology Sligo - Dept of Computing Power problem classificationPower problem classification

Institute of Technology Sligo - Dept of Computing Normal mode problem: -don’t pose a hazard to you or to your computer. Common mode problem: -Can go directly to computer’s chassis, they can damage data signals.

Institute of Technology Sligo - Dept of Computing Typical Power line problems:Typical Power line problems: Sag (brownout): - short term decrease in voltage level - duration : less than a second - cause: equipment startup (motors, elevators) -effects: lost or corrupted data, shrinking screen, equipment shutdown

Institute of Technology Sligo - Dept of Computing - Possible solutions: -relocate a computer to a different electrical circuit. - voltage regulators. - UPS.

Institute of Technology Sligo - Dept of Computing

Total power loss: - cause: excessive demand on power grid. -Lighting storms. -Ice on power lines -Car accidents - effects: system shutdown. - Possible solutions: - UPS.

Institute of Technology Sligo - Dept of Computing

Spike: - instantaneous increase in voltage (microseconds). -cause: nearby lighting strike, equipment cycle on or off. - effect: hardware damage, lockups, data loss. Solution: -surge suppressors

Institute of Technology Sligo - Dept of Computing

surge: - a short term increase in voltage (a few seconds) -cause: high- powered electrical devices is switched off. - effects:hardware damage, lockups, data loss Solution: -surge suppressors.

Institute of Technology Sligo - Dept of Computing

Oscillation (harmonics or noise): -unwanted electrical signal of high frequency form other equipment (RFI, EMI).

Institute of Technology Sligo - Dept of Computing Solution: -shortening power cable runs. -power line filtration. - cause: lighting, generators, radio transmitters, -disrupts the smooth sine wave expected from utility power. excessively long electrical wiring run. - effects: data loss, errors.

Institute of Technology Sligo - Dept of Computing

UPS - sag and brownout problems best addressed by UPS. -At minimum, every network file server should have a UPS. -Where possible a power backup should be provided for all work areas.

Institute of Technology Sligo - Dept of Computing 1. Standby (off-line or switched) ups Types of UPS: 2. On-line (continuous) UPS. 3. Line-interactive UPS.

Institute of Technology Sligo - Dept of Computing

Good Luck !