Data Cabling Techniques
24
Table 2 shows the five common modular cable specifications and their
applicability to 10BASE-T network use.
Table 2: Usable and Unusable Twisted Pair Cable
UTP Hub-to-MAU
Wiring
The AT-30xxTR models have 10BASE-T UTP ports with industry-standard
RJ45 receptacles. The standard network connection is from a Data
Communications Equipment (DCE) device, such as the repeater, to a DTE
device, such as a workstation Network Interface Controller (NIC). This
configuration uses a straight-through cable (see Figure 18).
Figure 19 shows a UTP cable with an RJ45 connector. For a 10BASE-T link
between a hub and a Media Access Unit (MAU) or NIC, the cable is wired
straight-through. That is, an RJ45 receptacle at the hub would wire pin-to-pin
to the RJ45 receptacle at the MAU, as shown in Figure 18 on the previous
page.
Cable
Level
Cable Description
AC
Character
Specification
Twist/
Foot
10BASE-T
OK?
1
Unshielded untwisted
N/A
CCITT
N/A
NO!
2
Individual UTP
100
Ω
±
30
Ω
RS232
10BASE5
AT&T PDS
N/A
NO!
3
Typical Individual UTP
100
Ω
±
15
Ω
TI, AT&T ISDN
10BASE-T
IBM Type 3
3-5
YES
4
Enhanced Individual
UTP
100
Ω
±
30
Ω
EIA, TIA
10BASE-T
NEMA
5-8
YES
5
Individual UTP
100
Ω
±
30
Ω
EIA, TIA
10BASE-T
8-10
YES
Figure 18: 10BASE-T UTP
Cabling Hub-to-MAU or NIC
(Straight-Through)
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
TD +
TD -
RD +
Not Used
TD +
TD -
RD +
Not Used
Not Used
Not Used
Not Used
Not Used
Not Used
Not Used
RD -
RD -
RJ45 PIN
RJ45 PIN
Per IEEE 802.3 specifications
