Allied Telesis AT-MR820T - Manual (Page 39)

AT-MR420T and AT-MR820T Installation Guide
17
UTP (RJ45) Connector
Figure 9 shows a UTP cable with RJ45 connectors. For a 10Base-T link
between a repeater and a Medium Attachment Unit (MAU) or Network
Interface Controller (NIC), the cable is wired straight through.
Figure 9: RJ45 Connector
10Base-T UTP cables can be 100 meters (328 feet). The cable should be
22 to 26 AWG UTP wire with 100
Ω
impedance. The repeaters use RJ45
modular connectors for 10Base-T connections.
10Base-T Cable. These micro repeaters supports full-length, fully
repeated transmission and maximum node attachments which, for the
UTP link, enables transmissions up to 100 meters (328 feet).
A serious problem exists concerning identification of modular cable.
There are various grades of voice-quality and data-quality cables
available. These can appear to be similar, but their high-speed data
transmission characteristics are radically different.
One reason for the identification problem is some suppliers have sold
purportedly data-quality cables manufactured with voice-quality
cabling.
If any voice-quality cabling is used in a 10Base-T network system, data
movement is slow, collision-prone or non-existent. To confuse the issue,
the Link indicator on the interface usually indicates a valid link in such
a case.
10Base-T connections require Category 3, 4, or 5 cabling. In most cases,
if a cable type is flat, it is typically untwisted and can cause problems.
Generally, cable that is round in section, gives better results.
MRx20T(UTP)Ver6_Book Page 17 Thursday, April 3, 1997 5:18 PM