3Com MSR 50 Series, Configuration Manual

Page: 202 / 2443

202 C
HAPTER
6: DCC C
ONFIGURATION
# In the [Network Connection Type] dialog, select the Accept incoming
connections option, and click <Next> to set the device for incoming connections.
Click <Next>. The [Incoming Virtual Private Connection] window appears.
# Select the Allow virtual private connections option if the server is connected to
the Internet to provide Internet access requests for the client. If otherwise, select
the
Do not allow virtual private connections . Then click <Next>.
# In the [Allowed Users] dialog, click <Add>. In the popup [New User] dialog add
the username and password for the PPP callback client and click <OK>. An icon
for the new user account appears in the box in the [Allowed Users] dialog.
# Select the new user and click <Properties>. The properties setting dialog
appears.
# Under the [Callback] tab, do one of the following:
■
Select the Do not allow callback option. After the PPP authentication is
passed in a call, this option prevents the callback server from disconnecting the
current connection and calling back. Instead, the server will maintain the
current connection and allow the client to access the LAN or the Internet.
■
Select the Allow the caller to set the callback number option. After the PPP
authentication is passed in a call, the server will disconnect and then call back
the client at the number configured in the
ppp callback ntstring dial-number
command. This option is almost the same as the last option except that the
charges are paid by the server end rather than the client end.
■
Select the Always use the following callback number option to set a
callback number.
Click <OK>. The [Networking Components] dialog box appears.
# Set the Networking components (use the default). Click <Next>.
# Assign a name to your connection and Click <Finish> to complete the creation.
Circular Dial String
Backup and Internet
Access with DCC
Network requirements
Figure 32 presents a scenario where:
■
Router A and Router B are connected across a PSTN network.
■
Router B works as an access server and is configured with an IP address of
100.1.1.254/24. It uses the address range of 100.1.1.1/24 to 100.1.1.16/24 for
address assignment. The PSTN dial strings available on it are 8810048 through
8810055, allowing the router to provide services to 16 online users.
■
Router A accepts the IP address assigned by Router B.
Configure Router A on the dialup side to implement cyclic dial string backup with
dialer routes. Configure Router B on the access side to use asynchronous serial
interfaces to provide DCC dialup access and adopt PAP to authentication the
dialup side.
Figure 33 presents another scenario where Router C and Router D are connected
across an ISDN network. The configurations of Router C and Router D are the