My manager wants me to get a Sharp SL-5500 PDA to connect to our wireless network running on a Cisco 3000 concentrator using VPN software. The question is this: I have tried to use movian VPN software that Cisco recommends but have had problems with it for the ipaq. Can you recommend some companies that have decent VPN software? Secondly I need to find a VPN client software that will run on the embedded Linux OS. Where can I find such software and can you give me some companies names that you would recommend?
PDAs like your iPAQ H3800 series running Pocket PC 2002 have plenty of VPN options. As you probably already know, a PPTP VPN client is built into PPC, and you could possibly use that with your Cisco 3000, but I'm guessing you want IPsec instead.
Standalone IPsec VPN clients for PPC are available from Certicom ( movianVPN) and Funk (AdmitOne). I'm surprised that you're having trouble with movianVPN, because it has been demonstrated to interoperate with the Cisco 3000, runs on the iPAQ, and has a reasonably broad set of security parameters. If you haven't already done so, ask Certicom support to help you work out your problems. AdmitOne is also a pretty fully-featured IPsec VPN client, so give it a try if you haven't already. There are other IPsec VPN clients for PPC that are paired with other vendor gateways (e.g., CheckPoint, V-ONE) and other higher-layer PPC clients (e.g., NetMotion, Symbol). But I think you want a standalone IPsec client to pair with your Cisco VPN concentrator.
I don't have any first-hand experience with the Sharp SL-5500 running embedded Linux, but here are two VPN software packages that I was able to find for that platform: Freeswan IPsec module and ZeeS/WAN. You may also want to visit this Zaurus FAQ page and follow links to various software indices.