Nortel Secure Router 8012
Hardware Description 5 Cables
Issue 5.3 (6 April 2009) Nortel Networks Inc. 5-5
5.5.1 Introduction
The Ethernet cable consists of two types: straight-through cable and crossover cable.
Straight-through cable
Straight through cable is also called standard cable. The wire sequences of the twisted pairs
crimped in the RJ45 connectors at both ends are the same. Straight-through cable connects a
terminal device (a PC or the router) to a hub or a LAN switch. The cables delivered with the
equipment are straight-through cables.
Crossover cable
Crossover cable is also called direct connection cable. The wire sequences of the twisted pairs
crimped in the RJ45 connectors at both ends are different. Crossover cable connects two
terminal devices (a PC or the router).
5.5.2 Structure
Both straight-through cable and crossover cable use shield cables and RJ45 connectors. Figure
5-3 and Figure 5-4 show the pin assignment.
Figure 5-3 Schematic diagram of straight-through cable
1
2
3
6
1
2
3
6
RJ45 RJ45
Figure 5-4 Schematic diagram of crossover cable
1
2
3
6
1
2
3
6
RJ45 RJ45
Table 5-3 and Table 5-4 describe the pin assignment of straight-through cable and crossover
cable.