3Com Router Module Guide
Chapter 2 Smart Interface Cards
2-17
2.4.6 Interface Cable
Interface cables for ROUTER 1-PORT FRACTIONAL E1 SIC are standard E1 G.703
cables. E1 G.703 cables have two types: 75-ohm non-balanced coaxial cables and
120-ohm balanced twisted pair cables, shown as follows:
z
75-ohm non-balanced coaxial cable
HUAWEI
BNC connector
Cable tie
Label
Magnetic core
Hot-shrinkable tube
DB15 Male
Enlarged A side
Pos.1
Pos.15
A
Figure 2-16
E1 G.703 75
-ohm
non-balanced coaxial cable
75-ohm non-balanced coaxial cable connects ROUTER 1-PORT FRACTIONAL E1
SIC with the DB15 connector and the network end with the BNC connector.
Note:
A pair of coaxial connectors are available for extending the E1 cable. Both ends of the connectors are
BNC receptacles that can be used to connect two 75-ohm non-balanced coaxial cables with BNC
connectors.
z
120-ohm balanced twisted pair cable
Figure 2-17
E1 G.703 120
-ohm
balanced twisted pair cable
120-ohm balanced twisted pair cable connects ROUTER 1-PORT FRACTIONAL E1
SIC with the DB15 connector and network end with the RJ-45 connector.