Connecting Wan Interface To Dsu/Csu - 3Com 5000 Series Installation Manual

3Com Router 5000 Family
Installation Guide
In general, the AUX port is used for remote configuration or dial-up backup. The local
Modem is first connected to the remote Modem through PSTN, and then to the remote
device.

4.8.2 Connecting WAN Interface to DSU/CSU

I. Connecting synchronous/asynchronous serial interface to DSU/CSU
1) Introduction to the synchronous/asynchronous serial interface
The fixed WAN interface of 3Com 5000 Routers is a synchronous/asynchronous serial
interface, which is usually used for the connection with a WAN device, such as a
Modem or CSU/DSU. It can operate in the synchronous/asynchronous mode or
DTE/DCE mode, depending on the application. For the attributes of the interface,
please refer to Table 4-6
Table 4-6 Attributes of the synchronous/asynchronous serial interface
Attribute
Connector type
Interface standard
and operating
mode
Minimum baud rate
(bps)
Maximum baud
rate (bps)
Matching cable
Function
Synchronous
DB28 or DB50
V.35/RS449/X.21
V.24
/RS530
DTE/DCE DTE/DCE
1200 1200
64K 2.048M
V.24 (RS232) DTE cable
V.24 (RS232) DCE cable
V.35 DTE cable
V.35 DCE cable
X.21 DTE cable
X.21 DCE cable
RS449 DTE cable
RS449 DCE cable
RS530 DTE cable
RS530 DCE cable
DDN leased line backup
Terminal access
3Com Corporation
4-12
Chapter 4 Installation of the Router
Description
Asynchronous
RS232
300
115200
Modem dial-up
Backup
Asynchronous lease
line
terminal access