3com 3C886 User Manual

C

HAPTER

 2: 56K LAN M

ODEM

 F

UNCTIONALITY

 D

ESCRIPTION

The main steps for creating a VPN are as follows. Each step is explained in detail in 
subsequent sections.

■

Set up the server side of the tunnel connection

■

Set up the client side of the tunnel connection

■

Initiate a tunnel between client and server using your client software

In order to establish a tunnel, the client side must be able to dial into a PPTP tunnel 
server on the remote private network such as a Windows NT server version 4.0 or 
later. If you use Windows NT 4.0, then Service Pack 3 or greater and RAS must be 
installed. Also, the protocols required for the private network must be installed on 
the PPTP tunnel server. It is recommended that an experienced network 
administrator set up the server side. Note that protocols required for the private 
network must be installed on each PPTP tunnel client as well as the PPTP tunnel 
server.

In order to establish a tunnel, the client side must have PPTP tunnel client software 
such as 3Com’s NETBuilder, PathBuilder, Total Control Hub. An additional 
requirement is Microsoft’s Windows Dial-Up Networking version 1.2 or higher 
which includes the required software VPN adapter, or Windows NT operating 
system with Service Pack 3, or Network TeleSystem’s TunnelBuilder™ VPN 
software for Windows 3.11 and Macintosh operating systems. This software 
should reside on all workstations that wish to create a tunnel to the tunnel server. 
Follow instructions provided for installation and set up.

If you are using Windows Dial-Up Networking version 1.2 or higher, the basic set 
up steps are as follows. (Refer to Windows user documentation for details.)

■

Install the PPTP protocol

■

Create a RAS phone book entry for the VPN

A RAS phone book entry is similar to other phone book entries with the 
exception of an IP address in the Phone number field. Once the Phone book 
entry is complete, you can double-click the icon to dial into a server that 
supports PPTP via any ISP.

Note that protocols required for the private network must be installed on each 
PPTP tunnel client as well as PPTP tunnel server.

As with PPP, no configuration is required on the LAN Modem to use PPTP. 
However, you must have an ISP configured on the LAN Modem.

Once the client side and server side are configured, you are ready to create a 
tunnel. The steps required for creating a tunnel vary depending on which client 
software you are using. Refer to the user documentation provided with your PPTP 
software to determine how to establish a tunnel. For instance, if you are using 
Windows Dial-Up Networking version 1.2 or higher, double-click the phone book 
entry for the VPN.

Once you attempt to create a tunnel, the LAN Modem detects this attempt and 
automatically places a call to your ISP. Once the call is connected, a tunnel is 
established between your workstation and the tunnel server.