SSL VPN vendor AEP is lining up support for clustering, load balancing, application firewalling and application assurance.

Via a licensing agreement with Zeus Technology, AEP will initially make it possible to tie together up to 10 of its NSP gateways that terminate SSL VPN tunnels. This means customers will be able to expand the capacity of their VPN 10-fold to support more than 10,000 concurrent users, according to the company.

It also means the clustered devices can back each other up so that if one fails, the rest pick up the load and the downed machine can be removed without taking the rest of them offline. AEP anticipates that the active/passive failover feature will be available in its products in the fourth quarter of this year.

Over the next year, AEP plans to make use of Zeus' load-balancing software that can split up traffic among several application servers so none gets more than their share, improving overall performance of server clusters. AEP will also use Zeus's application firewalling capabilities as well as its application performance technology to ensure applications remain reachable even when under heavy demand.

AEP says it is still up in the air whether it will put these new capabilities in one piece of hardware along with VPN software or make a separate device. Whatever it decides, it is another example of VPN vendors struggling to find other technology to sell that enhances their VPN gear.

Like other vendors that have reworked their hardware so it can support multiple security functions, AEP is also gathering multiple technologies. But AEP seems undecided whether the software should be deployed on one or multiple pieces of gear.

The difference can be significant for a business looking to protect its network because multiple devices require more management and administrative time. One possible upside is that putting the gear on multiple pieces of hardware gives customers more flexibility about which vendor they buy from.

And a possible upside of putting all these functions on a single platform is that it would add fewer devices to the network, keeping the architecture and management simpler. Over the next few months AEP will have to do its own calculations to determine which is the better choice for AEP and its customers.

Tim Greene is senior editor at Network World.