3Com 3C13751, Getting Started Manual

Page: 32 / 72

32 Chapter 2: Installation
Figure 14 AUX cable assembly
WAN Interface to
DSU/CSU
Introduction to the synchronous/asynchronous serial interface
The fixed WAN interface of the Router 5000 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 15.
Table 15 Attributes of the synchronous/asynchronous serial interface
Attribute
Description
Synchronous Asynchronous
Connector type DB28 or DB50
Interface standard and
operating mode V.24 V.35/X.21 RS232
DTE/DCE DTE/DCE
Minimum baud rate
(bps) 1200 1200 300
Maximum baud rate
(bps) 64K 2.048M 115200
Matching cable 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