A Virtual Private Network (VPN) works by creating encrypted tunnels through the Internet. This allows remote users to establish a connection to headquarters without having to deploy a costly private line solution. In an SSL-VPN, these tunnels are stateless; they can be created in real time and they last only for the duration of the connection.

Scaleability & Flexibility
For an organization to make full use of an SSL-VPN, the VPN should be able to maintain a variable number of connections. SSL-VPNs are meant to be flexible. At any given time, the number of connections may rise and fall, depending on demand and individual situations. An SSL-VPN solution must be scaleable and flexible enough to accommodate that.

Yet some vendors of SSL-VPN solutions don't seem to get it. They provide the flexible technology, but then take away that flexibility by charging a per-tunnel licensing fee.

Affordability
Celestix' SSL-VPN solution based on Microsoft IAG 2007 has a major advantage: Affordability. Unlike many others, who charge a per-tunnel licensing fee, Celestix/Microsoft SSL-VPN solutions have no restrictions on the number of concurrent user tunnels. However, a Celestix SSL is limited by the number of user licenses or "CALs."

What capacity do you need?
The Celestix WSA3000 is perfect for organizations with up to 1,000 employees and up to 500 simultaneous users. The WSA4000 is designed for larger environments with up to 2,500 employees and 1,000 concurrent users. The WSA6000 delivers capacity for up to 5,000 employees with a recommended maximum of 2,500 concurrent users. For top-end performance, Celestix recommends the WSA8000 for organizations that have up to 15,000 employees and up to 8,000 concurrent users. WSA SSL VPN appliances provide best-in-class performance, scalability, and redundancy for organizations requiring high-security access.

Model	Type of Business	Sizing
WSA3000	Designed for Small to mid-sized enterprises	Recommended for up to 1,000 users with max. 500 concurrent users
WSA4000	Designed for mid-sized to large enterprises	Recommended for up to 2,500 users with max. 1,000 concurrent users
WSA6000	Designed for large and multinational enterprises	Recommended for up to 5,000 users with max. 2,500 concurrent users
WSA8000	Designed for large and multinational enterprises	Recommended for up to 15,000 users with max. 8,000 concurrent users
WSA8000h	Designed for Government agencies	Recommended for up to 15,000 users with max. 8,000 concurrent users

For companies that require redundancy and enterprise-class uptime, please ask your Celestix sales representative about high availability options. WSA appliances can be clustered to support large numbers of concurrent users or for redundancy purposes.

The SSL-VPN delivers more power and more connections. While Celestix gives you an unrestricted capacity of concurrent users for a set price, other companies present a tiered pricing schedule based on the number of tunnels. Competing devices may have the same capacity, but you may end up paying twice as much--or more--depending on how many tunnels you deploy.

Note: Celestix' concurrent user counts are merely recommendations, not a hard-and-fast restrictions. In contrast, other SSL-VPN appliances will deny incoming connections when you reach the maximum number of connections in your license.