Ping tunnels, in a few words words, allow using of any wifi spot to send small quantities of data through the (always open) ping channel, a possibility that has been around for years (1).
Anyhow, a significant show stopper on Android is the fact that opening such a ping tunnel on a standard Android requires root access : in other words, even the most emergency-oriented applications (Briar, Signal, …) just cannot implement this unless it is on a rooted phone, and this point alone eliminates 95% of their user : a no-go.
The situation is quite different on /e/ OS : /e/ COULD implement a new raw socket for ping tunnelling, and propose it as just an extra possible channel to all apps, for all /e/ users and any other one that would propose such a tunnel (including home computers or routers).
An /e/ user, for instance, could declare itself a pingtunnel contact offering an access to internet through his/her normal GSM connection ; very few such users could ‘save the day’ in case of catastrophic access shortage.
All messaging apps, among others, that are definitely helpful in this kind of critical situation, would greatly benefit from pingtunnels, while they cannot implement them alone on closed android systems.
So, an integrated pigtunnel capacity would offer, immediately to all /e/ users
- an unique robustness to internet access shortages
- a very visible enhancement specific to /e/.
The purpose of this proposal is to evaluate our common interest in this potential addition of a pingtunnel capacity within /e/.
In summary :
- a pingtunnel capacity at system level in /e/ offers a way to connect other /e/ users and any pigtunnel server through any network, including closed wifi ones, with a small throughput sufficient for messaging apps
- only /e/ can develop it, not the stock android : this would be an unique specificity
- it may come extremely interesting in case of any crisis, allowing simple low-throughput accesses via almost any detectable network, whatever its ordinary access conditions.
Hoping the discussion will be motivating! 
Hervé
(1) https://www.cs.uit.no/~daniels/PingTunnel/,
http://www.debianadmin.com/access-network-when-everything-else-is-blocked-using-ptunnel.html,
https://github.com/f1vefour/ptunnel,
https://github.com/DhavalKapil/icmptunnel.
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