General Wiring Specification

Document History:
05/21/98 Rev 1.0 Prepared by: Todd Murchison

Cable Specifications

• Horizontal UTP runs must use - solid 4-pair 0.5 mm (24 AWG) cable.
• Runs must not exceed 90 meters (295 feet).
• Patch cords must use stranded cable for adequate flex-life.
• The total length of a channel (includes patch cords at both ends of the run) shall not exceed 100 meters (328 feet).

Termination Requirements

• Modular plugs and outlets should meet IEC 603-7 requirements. (Gold plating over nickel on connection surfaces.)
• All 4 pairs must be connected.
• Pin/pair assignment: T568A or T568B.

  	pin 1	white w/ green
  		green
  		white w/ orange
  		blue
  		white w/ blue
  		orange
  		white w/ brown
  	pin 8	brown
  
  

• Pair twists shall be maintained as close as possible to the point of termination. Untwisting shall not exceed 13 mm (0.5 in.) for category 5 links.
• Strip back only as much jacket as is required to terminate individual pairs.
• All outlets shall be securely mounted. Outlet boxes with unterminated cables must be covered and marked.
• The patch panel(s) and all outlets must be clearly labeled.
• Installed connectors shall be protected from physical damage and moisture.

Equipment Requirements

• Patch panels and networking equipment (Hubs, Switches, Routers) shall be mounted securely in 19-inch Telco racks.
• Telco racks must be securely mounted to the floor and wall if possible.

Testing Requirements

TSB-67 contains specifications for the verification of installed UTP cabling links which consist of cables and connecting hardware specified in the TIA-568A standard. The primary field test parameters for such a UTP link are:

• Wiremap
• Link length
• Attenuation
• Near-End Crosstalk or NEXT

Wiremap

This test assures the proper connectivity of a link. The test must assure that each connector pin from one end of the link is connected to the corresponding pin at the far end and is not connected to any other conductor or shield.

The Wiremap test must assure that the link maintains proper pairing of conductors and does not contain any "Split Pairs". A split pair wiring error occurs when connector pins which are supposed to be connected to a twisted pair for transmission are instead connected to wires that are not twisted together in a pair.

Link Length

The maximum length of a Basic Link shall be 90 meters (295 feet), plus 4 meters for the test equipment patch cords for a total of 94 meters. The total length of a channel shall not exceed 100 meters or 328 feet; when measuring a channel, the end-user patch cords are to be used and are to be plugged directly into the field tester.

Attenuation

Attenuation is the measure of signal loss along the cabling link. Attenuation changes with the frequency of the signal. A category 5 channel needs to be verified for signals ranging from 1 MHz to 100 MHz in maximum step size of 1 MHz.

Tests shall identify the worst case attenuation of each wire pair in an installed link and issue a Pass or Fail diagnostic by comparing the worst case against the allowable attenuation values.

NEXT

Near-End Crosstalk or NEXT Loss is a measure of signal coupling from one pair to another within a UTP cabling link. A category 5 link must be measured over the frequency range from 1 MHz through 100 MHz.

NEXT loss needs to be measured for each pair to each other pair in a UTP link. This equates to six pair combinations for the typical four pair cabling link.

Tests shall identify and report the NEXT value, frequency, and the limit value at which the worst case NEXT performance margin occurs for a pair combination.

The standard requires that the NEXT Loss of a link be measured from both ends of the link.

Category 5 UTP Cable Attenuation/NEXT Loss (worst pair)

	Frequency         (dB)
	(MHz)          Attn/NEXT

	0.064		0.8 /
	0.150		- / 74
	0.256		1.1 / -
	0.512		1.5 / -
	0.772		1.8 / 64
	1.0		2.0 / 62
	4.0		4.1 / 53
	8.0		5.8 / 48
	10.0		6.5 / 47
	16.0		8.2 / 44
	20.0		9.3 / 42
	25.0		10.4 / 41
	31.25		11.7 / 39
	62.5		17.0 / 35
	100.0		22.0 / 32

Drop Specification

• Each drop shall have 3 (24 AWG) cables terminated at the Outlet. One cable for the two voice (RJ-11) connections and one for each data (RJ-45) connection.
• All Outlets should be clearly labeled; 1000-1999, V=voice, D=data, A=first line, B=second line.