3Com 3C13751 Getting Started Manual page 33

Table 15 Attributes of the synchronous/asynchronous serial interface
Attribute
Function
Protocol
Synchronous/asynchronous mode
■
Synchronous/Asynchronous serial interface can work in either
synchronous or asynchronous mode. Different signalling standards are
supported in these two modes. V.35 and V.24 (RS232) support
synchronous operating mode, while V.24 (RS232), support the
asynchronous operating mode. The maximum transmission distance and
baud rate of the signal vary with the operating mode.
Table 16 Transmission rate and distance of V.24 (RS232)/V.35 cable
V.24 (RS232)
Maximum
transmission
Baud rate (bps) distance (m)
2400 60
4800 60
9600 30
19200 30
38400 20
64000 20
115200 10
- -
Description
Synchronous
DDN leased line backup
Terminal access
PPP
MP
LAPB
HDLC
X.25
Frame Relay
V.35
Baud rate (bps)
2400
4800
9600
19200
38400
56000
64000
2048000
Router to WAN Connection 33
Asynchronous
Modem dial-up
Backup
Asynchronous
lease line
terminal access
PPP
SLIP
MP
Maximum
transmission
distance (m)
1250
625
312
156
78
60
50
30