Stonesoft produced its own firewall a few years ago and has shown that it really understands the high end of the market.
StoneGate is built upon the concepts of clustering and high-availability. These are at the heart of the product, rather than being bolted on as an afterthought as with some products, which basically means that you have a robust firewall from the moment you install it.
Installation is possibly not the simplest around, but this is to be expected with a product of this complexity. The product is based on a hardened Debian distribution of Linux, and with the Java-based management console this means that it can be installed on virtually all operating systems.
The firewall consists of four components: the Engine, which is a stateful multi-layer inspection firewall, the Management Server, the Log Server and the Client. The latter three components can be installed on a single machine, or distributed around the network depending on your needs.
StoneGate's greatest asset has to be the idea of a 'heartbeat,' which is a constant communication between all of the engines in the configuration. This heartbeat means that every element of the StoneGate installation knows the state of every other element. If you have a complex network with multiple firewalls and multiple ISPs, this heartbeat of status information such as which nodes are online, and the throughput of each node, ensures that in the event of a traffic overload or an ISP connection failure, traffic can be diverted to another ISP instantaneously, ensuring continuity of business. All of this information is comprehensively logged and can be viewed in a variety of customizable formats.
Documentation is superb - a veritable library of information from a quick start guide to an in-depth user manual. And if that isn't sufficient for you, Stonesoft provides both extensive support and tailored training courses to ensure that your installation of the product is perfectly suited to your particular business needs.
Although not the simplest firewall in this Group Test, StoneGate is ideal if your network is mission-critical and you want high availability from day one. It is an excellent product; which is worth the money for the resilience it provides.