Specifications

Appendix B: Cables

NXA-ENET8POE Gigabit PoE Ethernet Switch

1000BASE-T Pin Assignments

All 1000BASE-T ports support automatic MDI/MDI-X operation, so you can use straight-through cables for

all network connections to PCs or servers, or to other switches or hubs.

The table below shows the 1000BASE-T MDI and MDI-X port pinouts. These ports require that all four pairs

of wires be connected. Note that for 1000BASE-T operation, all four pairs of wires are used for both transmit

and receive.

Use 100-ohm Category 5, 5e or 6 unshielded twisted-pair (UTP) or shielded twisted-pair (STP) cable for

1000BASE-T connections. Also be sure that the length of any twisted-pair connection does not exceed 100

meters (328 feet).

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, three

measures 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 current TIA (Telecommunications Industry Association) 568-A specification on optical fiber cabling

consists of one recognized cable type for horizontal subsystems and two cable types for backbone subsystems.

Horizontal 62.5/125 micron multimode (two fibers per outlet).

Backbone 62.5/125 micron multimode or single mode.

TIA 568-B will allow the use of 50/125 micron multimode optical fiber in both the horizontal and backbone in

addition to the types listed above. All optical fiber components and installation practices must meet applicable

building and safety codes.

1000BASE-T MDI-X and MDI Port Pinouts

Pin MDI-X Signal Name MDI Signal Name

1 Bi-directional Data Two Plus (BI_D2+) Bi-directional Data One Plus (BI_D1+)

2 Bi-directional Data Two Minus (BI_D2-) Bi-directional Data One Minus (BI_D1-)

3 Bi-directional Data One Plus (BI_D1+) Bi-directional Data Two Plus (BI_D2+)

4 Bi-directional Data Four Plus (BI_D4+) Bi-directional Data Three Plus (BI_D3+)

5 Bi-directional Data Four Minus (BI_D4-) Bi-directional Data Three Minus (BI_D3-)

6 Bi-directional Data One Minus (BI_D1-) Bi-directional Data Two Minus (BI_D2-)

7 Bi-directional Data Three Plus (BI_D3+) Bi-directional Data Four Plus (BI_D4+)

8 Bi-directional Data Three Minus (BI_D3-) Bi-directional Data Four Minus (BI_D4-)