Lesson 6: Installing a Physical Network

I. Understanding Structured Cabling

• structure cabling — set of standards used to install physical cabling, set by TIA/EIA

A. Cable Basics

• switch
• some UTP cable, and a few PCs
• star-physical network

i. Components to structured cable network set-up:

1. telecommunication room
2. horizontal cabling
3. work area

• run — a single piece of cable that runs from a work area to a telecomroom

a) solid core vs. stranded Core

UTP cable has two types:
* solid core — better conductor, stiff, easily broken
* stranded core — weaker conductor, lasts longer w/o breaking

b) number of pairs

• use highest CAT rating, 4-pair UTP for modern
• CAT5e, 4-pair only for TIA/EIA standard and above
• choose CAT5e or CAT6 UTP for current standard

c) Intermediate distribution frame (IDF)

• IDF is another name for the telecom room
• IDF vs. main distribution frame ( MDF)

Equipment racks for IDF:

• 10" width as standard, racks usu “42 U” in height
• use to store servers and even rack-mounted uninterruped power supplies (UPSs)
• uses height measurement unit “U”
• 1 U = 1.75 inches
• 2 U = 3.5 in space
• 4 U = 7 in
• most equip. on rack are 1U, 2U, or 4U

** path panel** — box of female connectors (ports) in front of perm. connectors.

• 110 block or 110 punchdown block
• 66 punchdown block for telephones
• TIA/EID 606 standard covers proper labeling, documentations
• best to get path panel CAT 6 since it is backward compatible with older CAT
• connects ports to switches with path cables

B. Structured Cable — Beyond Stars

• for multifloor connections, use backbone to connect to multispeed cabling
• telephone installation separate from networks
• usu. 25-pair UTP cable running 66-block in telecom room
• demarc — demarcation point, connections from outside world
• physical location of connection that marks the dividing line of responsibility for functioning of network
• network interface unit (NIU) serves as demarc btw your home network ISP
• ex: the DSL or cable modem by your ISP
• also called NI box, NI device = so NIU NIB NID means the same thing

C. Connections Inside the Demarc

• after the demarc, network and telephone cables connect to some type of box:
• cabling that runs NIU to –> box is a demarc extension
• ex: telephones = “multiplexer” box
• ex: LAN -switches which connect to path panel
• main pathc panel is a “vertical cross-connect”
• main distribution frame (MDF) — the room that stores all equipment for demarc, telephone cross-connects, and LAN cross-connects

II. Installing Structured Cabling

STEPS:
1. get a floor plan, blueprint
2. mapping the runs:
* cable drop — location where the cable comes out of the wall in the workstation
+ drop — single run nof cable from telecom room to hall. also mean a new run coming thru a wall outlet that does not have a jack yet

1. determine the location for telecom room with the followinng factors:

• distance — less than 90 ft
• power — ideally have its own dedicated circuit
• humidity — dry storage, low humidity
• cooling — provide AC, or other way to cool the room
  ex: A/C duct
• access:
• preventing unauthorized access
• expandibility

1. pulling cable

• usu telecom room –> drops

1. Making connections

• both ends connect to connect jack
• testing and labeling each cable

1. connecting the work areas

• crimp a jack into the end of the wire and mount face plate to complete installation

III. Testing Cable Runs

• cable testers — check continuity, break, teast wires on both end
• continuity testers = inexpensive, see if wire is broken
• wiremap test — test if wires are in the right spot at both ends
• pick up shorts, crossed wires
• multimeter for continuity:
• good connection — 0 Ohm
• no connection — infinity Ohms
• Time Domain Reflectometer (TDR)
• about $400, med-priced
• test continuity and wiremap, even identify where is the break on wire strands
• loopback device to test with installed cables
• high-end devices test for crosstalk and attenuation:
• near end crosstalk — electricity detector emits signal, listen to othe rthree pair
• far end cross talk — listens on the other end of port
• measure in decibels (db)

IV. Testing Fiber Cables

• fiberoptic runs don’t have crosstalk or EMI
• optical time domain reflectometer (OTDR) determine if cables break
• finding continuity and how far down the cable to look for the break

A. Three Fiber Optic Cabling Issues:

1. attentuation — when light disfuses, causing dispersion
2. light leakage — happens when cables bend
3. modal distortion — only in MMF cable

• mode means direction
• send different light modes

Attentuation vs Dispersion:
* attentuation is the weakening of signal over long cables/distance whereas dispersion happens when signal spreads out over long distance
* both are caused when the wave signal travel too far w/o fiber optic media
+ dispersion can cause attentuation and vice versa (confusing)

V. NICs

• all UTP Ethernet NICs uses RJ-45 connectors ( or 8P8C in nerdtalk)
• fiber-optic NICs — many choices

When buying NICs:

• PCI — peripheral component interconnect, expansion slot for NICs
• PIC — older PCs
• PCIe = “express” PCI, common usually one-lane (1x) or two-lane (2x)
• also keep USB NIC handy since they are good for troubleshooting:
• USB 2.0 max sped 480 Mbps
• USB 3.0 max speed 5 Gbps
• drivers — usu. with CD
• bonding — or link aggregation allows the use of the multi MICs for a single machine, doubles spped btw machine + switch
• Link Aggregation Control Protocol (LACP) controls how multiple network devices send and receive data as a single connection

Link lights

• from LED on NIC, diff color gives clues about the link
• tells you the speed of connection
• activity light — flickering light means card detects network traffic
• link light — connection light, must be steady and on flickering means issues
• ** collision light** — flickers when collision occurs