3com 2500 Quick Setup Guide

C

HAPTER

 4: C

ABLING

The 10BASE-T (RJ-21) module provides eight 
10BASE-T connections with one Telco connector. 
The connections are implemented as MDI-X (media 
dependent interface crossover) connections, 
meaning that a workstation or other DTE can be 
directly connected to the port with a 
straight-through cable. 

To cable the 10BASE-T (RJ-21) module:

Insert the mounting post and washer into the 
threaded hole of the cable end of the male Telco 
connector.

Connect the male Telco connector on the 10BASE-T 
cable to the female Telco connector on the module. 
Ensure that the slide latch is to the right.

Slide the latch to the left and ensure it grips the 
mounting posts.

Tighten the connector securing screws.

Attach the other end of the 10BASE-T cable in one 
of these ways:

■

Attach it to a harmonica panel with RJ-45 ports, 
as described in the next section. 

■

Punch the individual wires into a Type 66 or Type 
110 punch-down block, as described on page 4-5 
in 

(RJ-21) module using 10BASE-T cable.

Figure 4-2   Cabling the 10BASE-T (RJ-21) Module

Up to three modules with RJ-21 connectors can 
connect to a single harmonica panel, each through 
a 50-pin connector. Each harmonica panel provides 
24 RJ-45 connections for various network devices. 

 shows the RJ-45 connections on the front 

 shows the back 

of the panel, including the connections for the 
50-pin connectors. Harmonica panels are available 
from 3Com. 

Port Status

Active

Error

1

2

3

4

5

6

7

8

Inserted

PCMCIA

ard

or

Port Status

Active

Error

RJ-21 connector

10BASE-T (RJ-21)
module

10BASE-T cable

Securing screws