Specifically, at my usual location, I have an IPv6 network which connects to the Internet via a static tunnel set up to Hurricane Electric's tunnel broker ( http://www.tunnelbroker.net/ ). This works essentially perfectly, allowing inbound and outbound connectivity.
Now, however, I need to connect back to host(s) on that network over IPv6 from mobile tablet(s); meaning the conditions are such that there is no guarantee or even likelihood of native IPv6 support where it happens to be at any given time, and the IPv4 address of the tablet will change on a fairly regular basis.
The native Teredo support, as configured by default, functions well enough to let me ping my target hosts, but appears to have neither the reliability nor the throughput to support anything else; I have been unable to make any actual connections (trying a number of TCP-based protocols) using it.
I had considered setting up an independent tunnel for the tablet(s), and using scripts to update the client endpoint IP address when it changes, but since both (a) many of the locations will be behind NAT devices over which I have no control, and (b) the option over which I do have control is an AT&T Unite hotspot which does not offer protocol 41 forwarding or respond to ICMP on its public address, this approach does not seem viable.
I am additionally constrained as the mobile tablet(s) in question are Surface RTs, and as such are incapable of running, for example, AICCU client software.
What is my best option to pursue to obtain IPv6 connectivity in this scenario?