Here is an odd issue that seems to be limited to a restriction Sprint is imposing. I configured a L2TP VPN to our Sonicwall at work. If I disable the 3g/4g and run off Wifi on any connection (hotel, home, starbucks) the VPN connects and passes traffic just fine. I can run my SIP application, RDP, and ping devices on the VPN and Internet. All other Internet functions on the phone work as needed over WIFI

If I disable the Wifi and run off 3g or 4g, the same L2TP vpn will say connected, show on my SonicWall that it is connected with an IP, but I cannot ping anything on the Internet or remote VPN, I cannot run RDP or the SIP phone client either. I can however still access the standard Internet features via my phone (exchange , IE, etc)

I have found a few other posts on other sites stating that phone companies place 3g/4g users in restricted IP blocks thus blocking some traffic etc...

I have been on the phone and spoke to 3 different people at sprint over the course of the last hour. The first two had never heard of a VPN , let alone L2TP. The 3rd "heard" of a VPn but knew nothing more than that.

Anyone have any ideas??

 

Bingo!! That did it. My sprint TV and everything else still seems to work. Data speeds are faster, I can ping over the VPN and connect with the SIP phone.