Triplett TVR10/100/1000 User Manual

Page 36

Summary Twisted Pair (TP) Wire Connection Chart

Twisted Pair cables connecting:
PC to Hub/Switch

Straight thru

PC to PC

Crossover

Hub/Sw to Hub/Switch Crossover

Note: Because the Base-T standard has a mix of crossover and
straight thru cables, many opportunities arise for the pairs to get
“ﬂipped.” The TVR1000 3 jacks can quickly simulate a straight thru
and crossover connection to test for the proper cabling solution.

USOC vs AT&T Wiring Conﬁgurations Of all the combinations
of 8 position modular connector wiring schemes, two have become
popular enough to gain name recognition status. Of the two, only
“AT&T” can be used for 10, 100, 1000 Base-T systems. The differ-
ence is the pairing of signals on the cable (pairs are twisted together
for noise immunity).

●

USOC paired conﬁguration. A standard for telephones, this

conﬁguration is never used to connect network devices. The
pinouts do not match what is required for Ethernet.

●

AT&T paired conﬁguration (also known as AT&T 258A, EIA

(TIA) 568B, Twisted Pair Networks). The older 10Base-T
standard deﬁned and required pairs 1, 2 and 3, 6 to be wired but
all new cabling almost always includes the other two pairs (4,5
and 7,8). This is because some 100 Base-T schemes and all
1000 Base-T schemes use all 4 pairs. A “crossover” version of
“AT&T” is also quite common. Both straight thru and crossover
diagrams are shown.