A Virtual Private Network (VPN) works by creating encrypted tunnels through the Internet, allowing 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, they 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, and 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's SSL-VPN solution based on Microsoft IAG 2007 has a major advantage: Affordability. Unlike many others, which charge a per-tunnel licensing fee, Celestix/Microsoft SSL-VPN solutions have no restrictions on the number of concurrent user tunnels, however, it is limited by the number of CALs.

What Is the Capacity?
The Celestix WSA3000 is perfect for organizations with 1,000 employees or fewer and is recommended for 200 or fewer simultaneous users. The WSA3000 is designed for larger environments with up to 500 concurrent users and can accommodate the needs of organizations with 2,500 or less employees. The WSA6000 rounds out the product line with a recommended maximum of 1,500 concurrent users and is ideal for organizations with less than 5,000 employees. Also, WSA6000 provides best-in-class performance, scalability, and redundancy for organizations requiring high volume secure 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 Governement 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.

It's important to note that Celestix's concurrent user count is merely a recommendation, not a restriction. In stark contrast, other SSL-VPN appliances will deny incoming connections when you reach the maximum number of connections in your license.