Hello, let me first apologize if this information is already "out there" some place. I have been looking and have just not found out whether it is possible to make this work or not. Background information, have had the 4150L for probably about a year and haven't had a bit of trouble with it. I just updated the firmware this morning and it still seems to be working great. This is the first upgrade I have ever done to it. Anyway, what I am trying to accomplish, I have discovered that I can remotely connect to my office computer through my iPad using itap RDP and a VPN connection. I have already been able to use itap RDP in the office to show patients their x-rays etc... on the iPad. I have a cisco RVO82 router and my office software suggests the use of a PPTP VPN to connect remotely. I have checked all the settings and I have everything set as described. The iPad shows a VPN connection icon but when I try to connect to my computer, I get a TCP error. From what I have read, some people are able to connect via VPN on the 4150L and others are not. I cannot tell exactly how they are doing it. I read the double NAT stuff and am not sure if that is what my problem is, or if this is just not possible to do given my system. I am happy to try and get any other information you would, but you will probably have to tell me how to get it. I do appreciate any suggestions you may have, or, if I just can't do this, thanks for reading.
VPN connections will work with the MiFi 4510L, but it seems that a little extra configuration is needed in some scenarios. What appears to be the most consistent solution is to configure your Cisco Router/VPN to enable NAT-Traversal. With this feature enabled your Cisco Router should allow incoming connections from the MiFi.
Before you jump into the MiFi troubleshooting I suggest you contact Cisco for support. Cisco has a great community forum where I'm sure an expert can respond and resolve this for you. The actual Cisco support folks should be able to walk you through configuring your VPN and Cisco Router to allow everything through too.
Otherwise feel free to post your actual TCP error that you see when trying to connect to your remote PC. We can try to lookup the error message and further confirm where the problem lies.