Q: What are SSL-based VPNs? What makes them different? Are there limitations when using them compared to a normal VPN? --TechRepublic member who requested anonymity Salamone: The Secure Sockets Layer (SSL) VPN is a relatively new concept that's gaining interest in some corporations. The idea behind SSL-based VPNs is to use the encryption technology embedded in a Web browser to provide a secure connection to corporate data or applications. The market for SSL-based VPNs is somewhat small compared to traditional IPSec VPNs, but it is growing. According to the market research firm Infonetics Research, sales of SSL-based VPN equipment will reach $871 million by the end of 2005. In contrast, revenues for all VPN equipment were $1.3 billion in 2001. As I noted in the recent article "SSL-based VPNs are gaining favour," a major limitation to the SSL-based approach is that users can access only Web server applications. In contrast, an IPSec VPN would provide access to all resources, including client/server and legacy applications. While some might find the limitations of SSL-based VPNs a major hurdle, the shortcoming may quickly diminish as many companies move to Web services-enabled applications. Such applications would be accessible using the SSL-based VPN approach. For now, companies requiring secure access to Web applications might want to consider the SSL-based VPN approach as a simpler and easier-to-use alternative to the traditional IPSec VPNs.






