LANCOM 821+ – LANCOM 1711+ VPN – LANCOM 1721+ VPN Chapter 1: Introduction10ENThis is facilitated by splitters which separate the voice frequencies from thedata frequencies.1.2 What does VPN offer?For LANCOM1711+ VPN andLANCOM 1721+VPN onlyA VPN (Virtual Private Network) can be used to set up secure data communi-cations over the Internet. The models LANCOM 1721+ VPN and LANCOM 1711+ VPN are fac-tory equipped to support VPN with 5 active tunnels. With the addi-tional LANCOM VPN Option, VPN support can be extended to 25active tunnels (incl. activated hardware accelerator).The following structure results when using the Internet instead of direct con-nections:All participants have fixed or dial-up connections to the Internet. Expensivededicated lines are no longer needed. All that is required is the Internet connection of the LAN in the headquar-ters. Special switching devices or routers for dedicated lines to individualparticipants are superfluous. The subsidiary also has its own connection to the Internet.HEADQUARTERVPN GATEWAYLAN SERVERLAPTOPINTERNETVPN ROUTER ROUTERBRANCHLAN