3Com MSR 50 Series Configuration Manual page 181

[RouterA] interface serial 2/1
[RouterA-Serial2/1] physical-mode async
[RouterA-Serial2/1] async mode protocol
[RouterA-Serial2/1] dialer circular-group 0
[RouterA-Serial2/1] quit
# Set interface Serial 1/0 to work in asynchronous protocol mode and assign it to
dialer circular group 0.
[RouterA] interface serial 1/0
[RouterA-Serial1/0] physical-mode async
[RouterA-Serial1/0] async mode protocol
[RouterA-Serial1/0] dialer circular-group 0
[RouterA-Serial1/0] quit
# Enable modem dialup on user interfaces to be used.
[RouterA] user-interface tty1
[RouterA-ui-tty1] modem both
[RouterA-ui-tty1] quit
[RouterA] user-interface tty2
[RouterA-ui-tty2] modem both
2 Configure Router B.
# Configure a dial access control rule for dialer access group 1.
<RouterB> system-view
[RouterB] dialer-rule 1 ip permit
# Set interface Serial 2/0 to work in asynchronous protocol mode.
[RouterB] interface serial 2/0
[RouterB-Serial2/0] physical-mode async
[RouterB-Serial2/0] async mode protocol
# Assign an IP address to interface Serial 2/0, associate dialer access group 1 with
the interface, enable C-DCC, and configure two dial strings for calling Router A.
[RouterB-Serial2/0] ip address 100.1.1.2 255.255.255.0
[RouterB-Serial2/0] dialer enable-circular
[RouterB-Serial2/0] dialer-group 1
[RouterB-Serial2/0] dialer route ip 100.1.1.1 8810048
[RouterB-Serial2/0] dialer route ip 100.1.1.1 8810049
[RouterB-Serial2/0] quit
# Enable modem dialup on the user interface to be used.
[RouterB] user-interface tty1
[RouterB-ui-tty1] modem both
3 Configure Router C
# Configure a dial access control rule for dialer access group 1.
<RouterC> system-view
[RouterC] dialer-rule 1 ip permit
DCC Configuration Example 181