SMC Networks SMC8126PL2-F Fiber Standards, Cable Testing for Existing Category 5 Cable, Itu-T

B Cables

Cable Testing for Existing Category 5 Cable

Installed Category 5 cabling must pass tests for Attenuation, Near-End Crosstalk (NEXT), and Far-End Crosstalk (FEXT). This cable testing information is specified in the ANSI/TIA/EIA-TSB-67 standard. Additionally, cables must also pass test parameters for Return Loss and Equal-Level Far-End Crosstalk (ELFEXT). These tests are specified in the ANSI/TIA/EIA-TSB-95 Bulletin, “The Additional Transmission Performance Guidelines for 100 Ohm 4-Pair Category 5 Cabling.”

Note that when testing your cable installation, be sure to include all patch cables between switches and end devices.

Adjusting Existing Category 5 Cabling to Run 1000BASE-T

If your existing Category 5 installation does not meet one of the test parameters for 1000BASE-T, there are basically three measures that can be applied to try and correct the problem:

1.Replace any Category 5 patch cables with high-performance Category 5e or Category 6 cables.

2.Reduce the number of connectors used in the link.

3.Reconnect some of the connectors in the link.

Fiber Standards

The International Telecommunication Union (ITU-T) has standardized various fiber types for data networks. These are summarized in the following table.

Table B-3 Fiber Standards

ITU-T	Description	Application
Standard
G.651	Multimode Fiber	Short-reach connections in the
	50/125-micron core	1300-nm or 850-nm band
G.652	Non-Dispersion-Shifted	Longer spans and extended reach.
	FiberSingle-mode, 9/125-micron core	Optimized for operation in the
		1310-nm band. but can also be used
		in the 1550-nm band
G.652.C	Low Water Peak	Longer spans and extended reach.
	Non-Dispersion-Shifted Fiber	Optimized for wavelength-division
	Single-mode, 9/125-micron core	multiplexing (WDM) transmission
		across wavelengths from 1285 to
		1625 nm. The zero dispersion
		wavelength is in the 1310-nm region.

B-4