Black Box LGS103AE, Installation Manual

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C
HAPTER
B
| Cables
Twisted-Pair Cable and Pin Assignments
1000BASE-T P
IN
A
SSIGNMENTS
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).
Table 18: 1000BASE-T MDI and MDI-X Port Pinouts
Pin MDI Signal Name MDI-X Signal Name
1 Bi-directional Pair A Plus (BI_DA+) Bi-directional Pair B Plus (BI_DB+)
2 Bi-directional Pair A Minus (BI_DA-) Bi-directional Pair B Minus (BI_DB-)
3 Bi-directional Pair B Plus (BI_DB+) Bi-directional Pair A Plus (BI_DA+)
4 Bi-directional Pair C Plus (BI_DC+) Bi-directional Pair D Plus (BI_DD+)
5 Bi-directional Pair C Minus (BI_DC-) Bi-directional Pair D Minus (BI_DD-)
6 Bi-directional Pair B Minus (BI_DB-) Bi-directional Pair A Minus (BI_DA-)
7 Bi-directional Pair D Plus (BI_DD+) Bi-directional Pair C Plus (BI_DC+)
8 Bi-directional Pair D Minus (BI_DD-) Bi-directional Pair C Minus (BI_DC-)
C
ABLE
T
ESTING FOR
E
XISTING
C
ATEGORY
5 C
ABLE
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.