3Com 3C13701 3C13751 3C13755 3C13759 3C13840 3C13880 Network Router User Manual


 
3Com Router 5000 and Router 6000 v2.41
Module Guide
Chapter 4 Flexible Interface Cards (Router 6000)
4-24
In addition, you are available with 75-ohm-to-120-ohm adapters.
( Note:
E1 cable, coaxial connector, network connector, and 75-ohm-to-120-ohm adapter are all optional
accessories. They are provided only when ordered.
II. Interface cable of the Router 4-Port CE1/PRI FIC
Router 4-Port CE1/PRI FIC provides two types of 1-to-4 adapter cables: 120-ohm 4E1
and 75-ohm 4E1. At one end of both cables is a DB-25 connector for connecting the
router, and at the other end are four DB-15 connectors for connecting E1 cables. You
can distinguish between them by the main label text: “4E1-120Ohm-CAB“ for the
120-ohm 4E1 adapter cable and “4E1-75Ohm-CAB” for the 75-ohm 4E1 adapter
cable.
As shown in the following two figures, both cables look similar except that the 75-ohm
4E1 adapter cable uses eight coaxial cables but the 120-ohm 4E1 adapter cable uses
four twisted-pair cables.
Figure 4-27 120-ohm 4E1 adapter cable