An alternative is a software firewall. Most programs are available at a nominal cost, others are available for free. Popular firewall programs include BlackIce Defender , ZoneAlarm , Norton Internet 2000 and McAfee 's VirusScan or Guard Dog. Configure IP routing. It is possible to configure IP routing so that you can set up a firewall system in an environment separate and isolated from operational networks and specify permitted connectivity while denying all other connectivity.
Encryption software encodes data for sending then decodes it for reading.
A VPN enables corporate users to establish secure tunnels between their homes and their corporate LANs. This is a good solution for telecommuters. An IP address can be dynamically assigned to the end user from a pool of addresses during a PPP session initiation. The PPP over ATM and tunneling aspects are generally good for security, in the sense that these can provide virtual partitioning of the overall broadband platform. Although, at first glance, this would seem less secure than PPPoA because it's 'shared' in much the same way as a cable modem, there are no additional risks.