Chapter 4 – Cisco Semester I Wiring Closets IDF and MDF Metrics

Behavior Objective Students will document work Stress importance of good documentation Stress adherence to wiring Do’s and Don’ts Students will document work Students will follow standard procedures

Learning Objective Develop knowledge base to enable students to design networks that perform well Students will learn design concepts Students will gain confidence completing wiring tasks

Content Network Design Topologies Logical Physical Token Ring (single ring) FDDI (dual ring) Ethernet (logical bus) – largest % of installations Physical Star and Extended Star Both Ethernet and IEEE specify Star Extended Star requires additional wiring closets

Content Continued Wiring and electrical standards ANSI EIA/TIA 569-A ISO/NEC Wiring closet specifications Medium CAT 5 UTP for horizontal cabling

Why CAT 5 UTP Easy to use (not too thick but thick enough to hold up – unlike cheap net) Twists provide cancellation effect Relatively inexpensive Specified by both IEEE and Ethernet

Ethernet Network Speeds 10Base T 100 Base TX (aka Fast Ethernet) 1000 Base T (aka Gigabit)

Documentation Required Organization Information Who will use, computer skill level, network knowledge base, tasks performed Analysis and Problem Solving Information Gathered Cut Sheet – diagram floor plans Logical Design Map – IP addresses Physical Design Map – MAC addresses (devices), cable runs, outlets, etc.

DEVICES Layer 1 Layer 2 Layer 3 Hubs, repeaters (extend run beyond 99 meters) Transceivers – connect unlike devices Layer 2 Bridges -- reduce congestion and collision domain Switches – also provide virtual LAN and larger bandwidth Layer 3 Routers – segmentation – divide network into segments; reduce broadcast domain

Ground Basics Grounds are critical Can minimize ESD problem Remember ESC can destroy semiconductors and data Safety ground can prevent high voltage buildup GFCI (Ground Fault Circuit Interrupt)can cause circuit breaker to stop flow of electrons Grounds connected to chassis are not enough to protect computers and networks Also need UPS (Uninterrupted Power Supply) And Surge Protector

Wiring Basics One Hand Rule Common Fault Normal Fault Keep one hand in pocket when working with electrical devices to avoid creating a circuit with your body as the connection Electrical Current through the heart can kill Common Fault Hot Wire and Safety Normal Fault Hot Wire and Neutral Wire

Wiring Closet Specifications Near POP – to connect to outside world Centrally located – to minimize length of horizontal cable runs More important than being near POP Large enough to allow for expansion Raised floor To bring in horizontal cabling from work areas

Wiring Closet Continued Tile Floor Reduce dust, minimize static electricity No Dropped Ceiling Security Fire-Rated Plywood on Interior Walls Minimize fire risk (1.9 cm thick – 4.4 cm from wall) Controlled Humidity (30-50%) Controlled Temperature (21 C or 70 F)

More Wiring Closet Specs .9 Meter door that opens to hall Locked from outside but controlled from inside 50 candle foot lighting (preferably not fluorescent) – 2.6 meters above floor Light switch immediately inside door Two dedicated non-switched circuits Outlets every 1.8 meters (6 feet)

And Still More Closet Specs Ladder Rack to support Patch Panel Sufficient Floor Load capacity to bear weight of devices Ceiling and wall openings sealed with fire retardant material

Important Wiring Closet Info Need a wiring closet on every floor Need a wiring closet for every 1000 square meters of floor space Maximum length of horizontal cabling is 90 meters Add 3 meters to attach work station and 6 meters to attach to patch panel Total length – approx 100 meters

Multiple Wiring Closets Structured Wiring Designate primary wiring closet as MDF – Multiple Distribution Facility Hubs and Patch Panel in MDF or IMF Routers, switches, WAN connection in MDF Floor load requirements higher than IDF Vertical cabling (Backbone) will connect other wiring closets (IDF – Intermediate Distribution Facility)

MDF and IDF Location Good location can minimize horizontal cable runs Chosen location should minimize environmental problems Chosen location should make it easy to install and maintain network

Structured Wiring MDF known as Main Cross Connect Can have two levels of IDF (Intermediate) When there is only one level IDF Horizontal Cross Connect When there are two levels IDF connected to MDF is Intermediate Cross Connect Other IDFs connected to workstations are HCC There can be only one level between IDF for work stations and MDF

MDF – IDF Cabling Aka Backbone Cabling Between Buildings (InterBuilding) -- Single Mode Fiber preferred – 3000 meters Within Building (Intrabuilding) MultiFiber 62.5/125 u is recommended (568A) – 2000 meters – USED MOST OFTEN Other options (not preferred and not extensively used) 100 ohm UTP (four pair) 150 ohm STP (two pair) Coaxial cable is not recommended

Why Fiber for Backbone? Eliminates Problems Caused By: Different Voltage Potential in circuits served by different transformers (a grounding problem) Different transformers can serve circuits in same building Electrical strikes that could hit cabling between buildings Backbone includes connection to POP and Wiring Closets (from Patch Cords)

Special Backbone Considerations Run wire through conduit or sleeve If unable to run under floor Run sleeve above door level Total distance from MDF to workstations can’t exceed 3000 meters for single mode or 2000 for multimode fiber

Metric Reminder 1 Meter is approximately 39.?? Inches 1 decimeter = 1/10 meter 1 centimeter = 1/100 meter 1 millimeter = 1/1000 meter 10 meters = 1 decameters 100 meters = 1 hectometer 1000 meters = 1 kilometer