H3C MSR 20 Series Manual page 110

Interface Card and Interface Module Manual
H3C MSR 20/30/50 Series Routers
Step 3: Connect the other end of the E1 cable to the network device;
1) When using 75-ohm unbalanced coaxial cable,
Connect its BNC connector to the device to be connected directly, if cable
extension is not needed;
Connect its BNC connector to a coaxial connector and the other end of the coaxial
connector to the device to be connected through a 75-ohm E1 trunk cable, if cable
extension is needed;
Caution:
Connect the local Tx wire in the E1 cable to the remote Rx wire and the local Rx wire to
the remote Tx wire.
Router
75-ohm non-balanced coaxial cable
Figure 3-35 Extending an E1 75-ohm unbalanced coaxial cable
If the port on the network device to be connected has a 120-ohm port, use a
75-ohm to 120-ohm adapter, or use a 120-ohm cable instead.
2) When using a 120-ohm balanced twisted pair cable,
Connect its RJ-45 connector to the RJ-45 port on the device to be connected
directly, if cable extension is not needed.
Connect its RJ-45 connector to a network interface connector and then the other
end of the network interface connector to the network device to be connected
through a 120-ohm E1 trunk cable, if cable extension is needed.
DB-15
BNC
Coaxial connector
3-26
Chapter 3 Multifunctional Interface Modules
Network
BNC
devices
such as DDN
75-ohm E1 trunk cable