SYsynctext·Oct 15, 2026
Interesting project, towards a decentralized Internet!
The heavy lifting is done in this function, pairing. You link your personal devices together, solid idea [0].
This Flipflop project relies on the Iroh library for NAT/Firewall puncturing, external address discovery and overlay networking. Connecting two 5G devices, without a coordinating central server is possible, but very hard. Iroh simply relies on a server which you could self-host. Cool stuff, we stress tested it a while ago and it somewhat worked.
NAT connectivity is unsolved. My university lab conducted one of the bigger puncturing studies a decade ago [1]. Recently, we also bought 40+ or something 4G and 5G SIM cards in Europe for puncturing [2]. My master student traveled Europe by bus to get these local SIM cards. He worked day-and-night to connect these weird symmetric 5G N
Read the rest
AT filter boxes and got it working. Simple sync collision and birthday paradox brute force... It all works sometimes, but insufficiently reliable for mass-adoption. You can't build a decentralized social media ecosystem on top. Like Iroh, best to use a central server. So then you have legal liability for your users. Unless an AI agent buys the server fully autonomously using Bitcoin, next years students got that working[3] :-)
[0] https://github.com/andunieee/flipflop/blob/62bb498520aacb60e...
[1] UDP NAT and Firewall Puncturing in the Wild, https://inria.hal.science/hal-01597969v1/document
[2] Mass Adoption of NATs: Survey and experiments on carrier-grade NATs, https://arxiv.org/html/2311.04658v2
[3] Self-replicating seedbox servers using programmable money, https://arxiv.org/abs/2609.05431