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

2. 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

3. 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

4. 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

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

6. 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

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

8. 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.

9. 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

10. 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

11. 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

12. 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

13. 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)

14. 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)

15. 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

16. 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

17. 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)

18. 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

19. 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

20. 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

21. 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)

22. 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

23. 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