4
Determine the sequence number of the DB-15 connector at the other end of the
4E1 conversion cable and connect it to E1 cable.
5
Connect the E1 cable to the remote device:
If you are using a 75-ohm unbalanced coaxial cable and:
■
You
do not
need to extend the E1 cable, connect the BNC connector of the
75-ohm unbalanced coaxial cable to the remote device directly.
■
You need to extend the E1 cable, connect the BNC connector of 75-ohm
unbalanced coaxial cable to a coaxial connector, then connect the other end
of the coaxial connector to the remote device through the 75-ohm E1 trunk
cable. Make sure that the end of the E1 coaxial cable that is marked TX is
connected to the cable of the remote device marked RX and that the end of
the E1 coaxial cable marked RX is connected to the cable of the remote
device marked TX. See Figure 10.
If the remote network device has a 120-ohm interface, you should use 75-ohm to
120-ohm converter, or use a 120-ohm cable instead.
If you are using a 120-ohm balanced twisted pair cable and:
■
You
do not
need to extend the E1 cable, connect the RJ-45 connector of
the 120-ohm balanced twisted pair cable directly to the RJ-45 interface of
the remote device.
■
If you need to extend the E1 cable, connect the RJ-45 connector of the
120-ohm balanced twisted pair cable to a network interface connector,
then connect the other end of the network interface connector to the
remote network device using a 120-ohm E1 trunk cable. See Figure 11.
Figure 17
Extension Connection of an E1 75-Ohm Unbalanced Coaxial Cable
Figure 18
Extension Connection of an E1 120-Ohm Balanced Twisted Pair Cable
6
Power on the router.
DB-15
Router
75-ohm non-balanced coaxial cable
Coaxial connector
75-ohm E1 trunk cable
BNC
BNC
Network
devices,
such as
leased line
DB-15
RJ-45
Router
RJ-45
120-ohm balanced twisted pair
Network interface connector
120-ohm E1 trunk cable
Network
devices,
such as
leased line
3Com Router Release Notes for V1.20
32