This is an incredible resource on NAT traversal in practice. I used it as a reference while building a server-assisted p2p-over-TCP[1] system. The post covers U

This is an incredible resource on NAT traversal in practice. I used it as a reference while building a server-assisted p2p-over-TCP[1] system. The post covers UDP but all of the theory applies to TCP as well – you just need some SO_REUSEPORT dual dial/listen magic so the code will look a bit different. Meta: The post alludes to this, but I think NAT traversal is an inaccurate and confusing term. I like “hole punching” a lot more as a general term. It gets the message across without the myopic connotation that it’s all about NATs – it isn’t. [1]: https://github.com/betamos/rdv https://github.com/betamos/rdv