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:
- telecommunication room
- horizontal cabling
- work area
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- 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
- IDF is another name for the telecom room
- IDF vs. main distribution frame ( MDF)
Equipment racks for IDF:
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- 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:
- get a floor plan, blueprint
- 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
- 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
- pulling cable
- usu telecom room –> drops
- Making connections
- both ends connect to connect jack
- testing and labeling each cable
- 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:
- attentuation — when light disfuses, causing dispersion
- light leakage — happens when cables bend
- 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