OBJECTIVES 1. Define horizontal cabling. 2. Describe backbone cabling. 3. List different types of backbone cable systems and describe their attributes

OBJECTIVESOBJECTIVES

1. Define horizontal cabling.2. Describe backbone cabling.3. List different types of backbone cable systems and describe their attributes.4. Describe a crossconnect panel.5. Describe procedures associated with proper cable management.

Figure 5-1: Structured Cabling System

Figure 5-2: Horizontal Cabling System Components

Table 5-1: Wire Colors for TC Crossconnect

Figure 5-3: Horizontal Crossconnect

Figure 5-4: Horizontal Cable Run Distances

4-pair, 100-ohm unshielded twisted-pair (UTP) cables.

The types of cables that are recognized by TIA for horizontal cabling are as follows:

2-pair, 150-ohm shielded twisted-pair (STP) cables.

2-fiber, 62.5/125-micron optical fiber cable.

Figure 5-5: Telecommunications Outlet Cabling Choices

Figure 5-6: UTP Pair Assignments for 8-Position Modular Jacks

LAB 13 OBJECTIVELAB 13 OBJECTIVEInstalling a Punch-down Modular Outlet

To understand how to install To understand how to install an RJ45 punch-down modular an RJ45 punch-down modular outlet on a section of 100-ohm outlet on a section of 100-ohm UTP cableUTP cable

The end of the cable needs to be prepared first. Once you have done that, simply disregard the instructions that pertain to connector or cable types that are not included in your parts inventory. Keep in mind that the unshielded twisted pair cable does not require the grounding clip to be installed. Use the stuffer cap for one side of wires, and the punch-down tools for the other side. Once the wires have been punched down, go ahead and install the second stuffer cap so that both halves of the jack look identical.

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Figure 5-7: Testing Modular Jack and Cable Continuity

Recall that the RJ45 cable from Lab procedure 6 was already checked. Any problems noted on this test should point to the newly created cable.

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Figure 5-8: Fitting the Outlet into the Wall Plate

Don’t worry about installing the modular jack upside-down, because the design of the wall plate will prevent this.

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LAB 13 QUESTIONSLAB 13 QUESTIONS

What does the instruction sheet 408-3354 indicate about keeping the wires twisted to within specific distances from the termination?

11


When using the steel-tip punch-down tool, what impact setting is recommended?

22


Are the wires cut on the inside or the outside of the wiring block?

33


How are dimensions indicated on the instruction sheet?

44

LAB 14 OBJECTIVELAB 14 OBJECTIVEAssembling Edge-Connector Modular Outlets

To understand how to assemble To understand how to assemble an RJ45 edge-connector modular an RJ45 edge-connector modular outlet on a section of 100-ohm outlet on a section of 100-ohm UTP cableUTP cable

Although you will be using 100-ohm UTP cable, this type of RJ45 modular outlet can accommodate STP cable of both the 100-ohm, 8-wire and 150-ohm (Token Ring), 4-wire systems. When installing the connector within the matching housing, your parts may either snap or screw together.

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Figure 5-9: Aligning the Connector and Housing

Figure 5-10: Removing 2 Inches of UTP Cable Jacket

A 110Connect arrangement comes with the edge connector already installed in the port housing and remains this way during the wiring. The AMP-BARREL arrangement requires that the edge connector be terminated prior to its being mounted into the housing. Both types of installations are covered in the instruction sheet.

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Don’t forget to install the two stuffer caps on the edge connector, regardless of how the wires were punched down. They help to protect the connections against exposure.

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Figure 5-11: Pushing the Jack Insert

As a rule, any housing that will not currently carry an active service would be outfitted with a blank insert, until a future need for expansion occurs. You will not be installing a face plate as part of this lab procedure.

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Figure 5-12: Testing Modular Jack and Cable Continuity


After reading the instruction sheet 408-3232, which edge connector (110Connect or AMP-BARREL) appears to be the easiest to install?

11


Which type of edge connector (110Connect or AMP-BARREL) requires termination prior to being installed in the housing?

22


Why is it a good idea to lace the middle wires into the edge connector first?

33


Which type of edge connector comes already installed in the port housing?

44

Figure 5-13: Work Area Components

Equipment cords should have the same performance capabilities as patch cords of the same type and category.

The important specifications related to work area cabling include:

When adapters are used, they should be compatible with the transmission capabilities of the equipment to which they connect.

Maximum horizontal cable lengths are specified using a maximum cable length of 3 meters (9.8 feet) for work area equipment cords.

Any application-specific components (such as splitters or baluns) cannot be installed as part of the horizontal cabling system. If used, they are located external to the telecommunications outlet or horizontal crossconnect.

The important points to remember about horizontal cabling subsystems include:

The proximity of horizontal cabling to sources of EMI must be taken into account.

Horizontal cable types that have been recognized by TIA/EIA T568A include:

The important points to remember about horizontal cabling subsystems include: (continued)

4-pair, 100-ohm UTP

2-pair, 150-ohm STP-A

2-fiber (duplex), 62.5/125 µm, or a multimode optical fiber such as 50/125 µm, which is permitted under TIA/EIA T568B

Multipair and multiunit cables are permitted, as long as they meet the hybrid/bundled cable requirements of TIA/EIA T568A-3.


Grounding must conform to all applicable local/federal building codes, as well as TIA/EIA 607.

ISO/IEC 11801 permits 120-ohm UTP, and 50/125 µm multimode optical fiber.

A minimum of two telecommunications outlets are required for each individual work area, such that:


The first outlet is wired to 100-ohm, twisted-pair.

The second outlet is wired to 100-ohm, twisted-pair, or to 150-ohm STP-A, or to 62.5/125 µm multimode fiber.


One transition point (TP) is allowed between different forms of the same cable type, such as in situations where under-carpet cable connects to round cable. This term is broader by definition in ISO/IEC 11801 than in TIA/EIA T568A. In addition to the transitions for under-carpet cabling, it also includes consolidation point (CP) connections.

Although additional outlets may be provided, they are considered to be in addition to, rather than replacements for, the minimum requirements of the standard.


For copper-based horizontal cabling, bridged taps and splices are not permitted. Splices are allowed for fiber, however.

Although 50-ohm coax is recognized by TIA/EIA T568A, it is not recommended for new cabling installations.

Figure 5-14: Backbone Cabling System Components

Figure 5-15: Telco Connector

Figure 5-16: Patch Panel with RJ45 Connectors

Figure 5-17: Cable Tidy Between RJ45 Panels

Figure 5-18: Patch Panel with ST Fiber Optic Connectors

Figure 5-19: Backbone Cable Types

4-pair, 100-ohm unshielded twisted-pair (UTP) cables.

The types of cables that are recognized by TIA for vertical backbone cabling are as follows:

2-pair, 150-ohm shielded twisted-pair (STP-A) cables.

2-fiber, 62.5/125-micron multi-mode optical fiber cable.

1-fiber, 9/125-micron single-mode optical fiber cable.

Figure 5-20: Backbone Configurations

Equipment connections to backbone cabling should be made with cable lengths of 30 m (98 feet) or less.

The important points to remember about vertical backbone cabling systems include:

The backbone cabling shall be configured in a star topology. Each horizontal crossconnect is wired directly to a main crossconnect or to an intermediate crossconnect, then to a main crossconnect.

The backbone is limited to no more than two hierarchical levels of crossconnects (main and intermediate). No more than one crossconnect may exist between a main and a horizontal crossconnect and no more than three crossconnects may exist between any two horizontal crossconnects.

The important points to remember about vertical backbone cabling systems include: (continued)

A total maximum backbone distance of 90 m (295 feet) is specified for high bandwidth capability over copper. This distance is for uninterrupted backbone runs. (No intermediate crossconnect).

The distance between the terminations located in the entrance facility and the main crossconnect shall be documented, and should be made available to the service provider.


Multipair cable is allowed, provided that it satisfies the power sum crosstalk requirements.

The proximity of copper-based backbone cabling to sources of electromagnetic interference (EMI) shall be taken into account.

Bridged taps are not allowed.


Recognized media may be used individually or in combination, as required by the installation. Quantity of pairs and fibers needed in individual backbone runs depends on the area served. Currently recognized backbone cables consist of:

100-ohm UTP cable

150-ohm STP-A cable

62.5/125 micron optical fiber cable (recall that the TIA T568B specification recognizes 50/125 µm multimode fiber)

single-mode optical fiber

Crossconnects for different cable types must be located in the same facilities.


In ISO/IEC 11801, the equivalent cabling elements to the main crossconnect (MC) and intermediate crossconnect (IC) are called the campus distributor (CD) and building distributor (BD), respectively.

Just as with horizontal cabling, two alternate backbone cabling types are allowed by ISO/IEC (120-ohm, twisted pair and 50/125 µm, multimode optical fiber).

Again, 50-ohm coaxial cabling is recognized by TIA/EIA T568A, but is not recommended for new installations.


Category 3.

The following are the currently recognized categories of UTP cabling by the TIA/EIA:

Category 4.

Category 5.

Table 5-2: Color Code for 100-Ohm UTP

All four pairs of a 4-pair cable should be terminated on an 8-position jack.

The following is a list of recommendations for the installation of 100-ohm UTP work area outlets:

All work area outlets should be terminated as either T568A or T568B.

Both ends of a line should be terminated by the same designation, either as TIA/EIA T568A or TIA/EIA T568B.

The suggested maximum allowable untwisting for CAT3 cable is 3 inches.

TIA/EIA T568A specifies that the maximum allowable untwisting of CAT4 cable is 1 inch, and for CAT5 cable, the maximum allowable untwisting is ½ inch.

The following is a list of recommendations for the installation of 100-ohm UTP work area outlets: (continued)

It is suggested that the maximum allowable untwisting for any category above CAT5 be less than ½ inch.

Always leave 1 to 3 feet of service loop for repairs, changes, moves, and additions.

The bend radius should be no tighter than four times the cable’s outside diameter (usually 1 inch).

The following is a list of recommendations for the installation of 100-ohm UTP work area outlets: (continued)

The bend radius for cables with more than four cable pairs is ten times the cable’s outside diameter.

Do not exceed 25 pounds of pulling tension on a 4-pair cable.

The following is a list of specifications for installing 100-ohm UTP cable:

Do not cut, or damage, the cable’s outer sheath when pulling it.

Follow the proper color code.

All of the hardware used should be of the IDC type.

Installation must be neat and well organized.

Document every phase of the installation, including the locations of all components.

The following is a list of specifications for installing 100-ohm UTP cable: (continued)

Label cable runs at their beginning, middle, and end for easy identification.

Figure 5-21: CAT5 Patch Cables

Poor data quality through various crossconnections

Cable design experts have zeroed in on several chronic problems that have, as their primary cause, bad patch cables being used somewhere along the data path. These include:

Communications networks bombarded with increased error rates and junk traffic

Severe crosstalk and attenuation problems

Generally degraded network performance

Quality testing

Today’s manufacturers are striving to differentiate their patch cable products through:

Tolerance buffers

Strain-relief boots

Snagless features

Quick turnaround on orders

Performance level warranties

Various colors

Icons

Cost

Manufacturers’ labels

User-friendliness

LAB 15 OBJECTIVELAB 15 OBJECTIVEInstalling and Testing a DB15 Connector

To understand how to install a DB15 To understand how to install a DB15 connector on transceiver cable for use connector on transceiver cable for use with 10base5 Thicknet systemswith 10base5 Thicknet systems

Figure 5-22: Tap/Transceiver Hybrid

Table 5-3: AUI Pin Assignments

Figure 5-23: Twisting the Foil Shield

If you are not wiring the shield to pin 8, strip one inch of foil shield from each end of the cable, without damaging any of the twisted-pair wires inside the shield. Again, use the tension scale/tape measure for accuracy. This leaves 1/4 inch of foil shielding intact, and 1 inch of the twisted pairs (with bare drain wire, where applicable) exposed at each end of the cable.

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Figure 5-24: Stripped STP Cable

Figure 5-25: Inserting a Wire into a Connector Pin

The edge of the crimper tool should line up evenly with the edge of the barrel portion of the pin.

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Figure 5-26: Lining Up the Crimper and Pin

If the wire is not tight, try rotating the pin a quarter turn, and recrimp the barrel.

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Figure 5-27: Orienting the Tabs for Crimping

Figure 5-28: DB15 Male Connector Pin Numbers

Table 5-4: DB15 Pin/Wire Assignments

Figure 5-29: Positioning the Insertion/Extraction Tool

Figure 5-30: Inserting a Pin with the Insertion/Extraction Tool

Figure 5-31: Completed DB15 Male Connector Wiring

Figure 3-32 includes a wired foil shield to pin 8.

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The multimeter should show an infinite resistance between any adjacent pins (or wires) with the exception of pin 8 and the foil shield, if applicable, and a short circuit on matching continuity checks. If it does not, the cable is not correctly prepared, and you may have to repeat this procedure. If the cable checks out good so far, continue with the remaining steps.

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Figure 5-32: Installing the Strain Relief

Figure 5-33: Positioning the Connector/Strain Relief

Make a preliminary check to be sure that none of the wires are blocking the screw holes.

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You don’t want to tighten these housing halves completely until after the next few steps.

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Figure 5-34: Fastening the Housing Halves Together

Now it’s time to install the female DB15 connector on the free end of the cable.

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Figure 5-35: Reading the Pin Numbers on a Female DB15 Shell

Figure 5-36: Completed DB15 Female Connector Wiring

Figure 3-37 includes a wired foil shield to pin 8.

TIPTIP

The multimeter should show an infinite resistance between any adjacent pins (or wires) with the exception of pin 8 and the foil shield, if applicable, and a short circuit on matching continuity checks. If it does not, the cable is not correctly prepared, and you may have to repeat this procedure. Remember that the cable checked good before you mounted the male hood. Any problems should be confined to the newly installed female connector shell.

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Make a preliminary check to be sure that none of the wires are blocking the screw holes.

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Figure 5-37: Fastening the Housing Halves Together

You don’t want to tighten these housing halves completely until after the next few steps.

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To recover usable parts, clip the connectors and store the remaining length of cable, and disassemble the hoods, strain reliefs, and end connector shells. Use the insertion/extraction tool to remove any male/female pins from the end connectors. Discard the used pins and twisted-pair fragments and recover all of the short screws, slide clips, metal clips, retaining screws, connector shells, housing hoods, and long screws.

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Describe the differences in how pins are numbered between male and female D connectors.

11


Why should the continuity check be done before installing the hood housings?

22


When disassembling the D connectors, which parts must be discarded?

33

Figure 5-38: IBM Token-Ring 150-Ohm STP Cable

Table 5-5: STP-A Balanced Mode Attenuation/NEXT Signal Loss

The physical design of 150-ohm STP-A cable should meet the following specifications:

The insulated conductor shall not exceed the diameter of .26 mm (0.102 inches) maximum.

Pair 1: green is tip, and red is ring.

Pair 2: black is tip, and orange is ring.

The cable shall be restricted to 2-pair only.

The color code for 150-ohm STP cable is as follows:

A panel with IDCs for termination of the building cables

Two types of crossconnect panels are generally used for STP patching:

An open panel with lock openings for 150-ohm, STP snap-type media interface connectors

Allow 1 to 3 feet ( 1/3 to 1 meter) of service loop for future adds, moves, and changes.

In either case, the installer needs to follow the manufacturer’s recommendations for making the terminations. Other recommendations should include:

For 19-inch (483-mm) rack-mounted crossconnect panel installations, allow room on the rack for possible telecommunications equipment associated with the 150-ohm STP cable.

Racks should have at least the following clearances for access and cable dressing space:

In either case, the installer needs to follow the manufacturer’s recommendations for making the terminations. Other recommendations should include: (continued)

30 inches (762 mm) in the rear

36 inches (915 mm) in the front

14 inches (356 mm) on the side

Always follow the manufacturer’s recommended termination methods.

The following list summarizes the most important recommendations for the installation of 150-ohm STP cables:

Maintain at least 1 meter (approximately 3 feet) of cable for a service loop.

Telecommunications closet design must follow TIA/EIA 569.

Patch cord lengths should be limited to 7 meters (approximately 23 feet).

Equipment cord lengths should be limited to 3 meters (approximately 10 feet).

Plan for those inevitable future changes by allowing sufficient space in closets, and elsewhere, to make them. Assure that all connections include the necessary cabling service loops to effect these changes, and to maintain category compliance.

To maintain proper cable management techniques, you should:

To maintain proper cable management techniques, you should: (continued)

Include the following items in your worksheet documentation for each installation:

Indicate the length of cable runs to each room.

In order to save hours of future troubleshooting, document all of your wiring and test results.

Also document any problems that may have occurred, along with any solutions that were found.

Include the following items in your worksheet documentation for each installation: (continued)

Differentiate between all primary and secondary outlet locations in your documentation, and include the station phone numbers for each access line.

Be sure to document the cabling color code, the wire color combinations for each line, and the relationships between the wire colors. This is very important in situations where colors have been converted at a distribution device.

Include the following items in your worksheet documentation for each installation: (continued)

Maintain the relationship of pairs and lines at the distribution device, and clearly label the lines if the distribution device does not have a valid marking scheme.

Note any special circumstances.

For future reference, remember to provide a copy of the documentation at the wiring location (near a distribution device) and to keep a copy for your records.

Be certain that all your cable runs are labeled in the middle, and at both ends, and clearly indicate the marking scheme on your worksheet.


Logically plan the system crossconnect points so that each individual channel can be tested without making additional or unnecessary connections, which would degrade system performance. This is also an important point for category compliance.

Avoid making quick fixes to any installation. Instead, use standard wiring practices to ensure that all connections can be easily found and identified, now and later. Crossconnections made in ceilings, for example, are not standard, and will probably be forgotten about and difficult to manage.



Make your wiring plan consistent throughout your documentation. Regardless of whether the installation calls for a simple or complex wiring plan, it must:

Be complete and orderly.

Be scrupulously maintained.

Be readily accessible.

Be decipherable by other installers.


Neatness is an essential ingredient of any installation. Therefore:

All wiring should be laid out methodically and consistently.

Closets should be kept clean, with adequate room to work.

Unused equipment, leftover materials, and miscellaneous items should be removed from all ERs and TCs to provide full access to the cabling and the equipment currently in use at these locations.

REVIEW QUESTIONSREVIEW QUESTIONS

How much extra cabling should be allowed for a service loop?

11


What types of cables are recommended by TIA to be used for vertical backbone cabling?

22


Where should cabling be labeled?33


What is the maximum recommended pulling tension on a 4-pair cable?

44


What is the maximum cable length from a user outlet to a station device?

55


Hubs are connected together to the crossconnect facilities using “riser” or _____________.

66


State the color code for an 150-ohm STP cable.

77


How much of a CAT3 cable can be untwisted? CAT4? CAT5?

88


What type of topology is horizontal cabling?

99


Define horizontal cabling.1010

Documents

OBJECTIVES 1. Define horizontal cabling. 2. Describe backbone cabling. 3. List different types of backbone cable systems and describe their attributes