3Com 3C13751, Getting Started Manual

Page: 33 / 72

Router to WAN Connection 33
■
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.
Function DDN leased line backup
Terminal access
Modem dial-up
Backup
Asynchronous
lease line
terminal access
Protocol PPP
MP
LAPB
HDLC
X.25
Frame Relay
PPP
SLIP
MP
Table 16 Transmission rate and distance of V.24 (RS232)/V.35 cable
V.24 (RS232) V.35
Baud rate (bps)
Maximum
transmission
distance (m)
Baud rate (bps)
Maximum
transmission
distance (m)
2400 60 2400 1250
4800 60 4800 625
9600 30 9600 312
19200 30 19200 156
38400 20 38400 78
64000 20 56000 60
115200 10 64000 50
- - 2048000 30
Table 15 Attributes of the synchronous/asynchronous serial interface
Attribute
Description
Synchronous Asynchronous