3Com 3C13755-US - Router 5642 Installation Manual page 18

16 C 2: I
HAPTER NTRODUCING
Introduction to DTE and
DCE
R 5012 SIC
OUTER S
Table 13 Baud Rate and Transmission Distance of V.24 (EIA/TIA-232)/V.35 Cable
V.24 (EIA/TIA-232)
Baud Rate (bps)
64000
115200
-
The baud rate cannot exceed 64 kbps if the V.24 cable is used and the interface
operates in synchronous mode.
The synchronous serial port supports both data terminal equipment (DTE) and
data circuit-terminating equipment (DCE) operating modes. If two devices are
directly connected and one operates in the DTE mode, the other will operate in
the DCE mode. The DCE device provides the synchronous clock and specifies the
communication rate. The DTE device receives the synchronous clock and
communicates at the specified rate. Generally, the router is used as a DTE device.
To make sure that the device is a DTE or DCE, refer to the manual shipped with
this device. Table 14 provides additional information to help you identify the type
of the device.
Table 14 Typical DTE and DCE Equipment
Equipment type
DTE
DCE
An asynchronous serial port is generally used as dialing port and is connected to a
modem or a terminal adapter (TA). In this case, regardless of the operating mode
of the device, you need to select only the appropriate baud rate for the port.
Figure 12 illustrates the 1-Port Serial SIC.
Figure 12 1-Port Serial SIC
V.35
Maximum
Transmission
Distance (m) Baud Rate (bps)
20 56000
10 64000
- 2048000
Interface type
male
female
Maximum
Transmission
Distance (m)
60
50
30
Typical equipment
PC, router
modem, multiplexer,
CSU/DSU