Instruction manual

Publication date: Feb., 2012
Revision A1
31
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).
Table 12: 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-)
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: T
h
at w
h
en testing your ca
bl
e insta
ll
ation,
b
e 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.