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Sockets, TCP sockets, are TCP packets in a stream of a given format. TCP is layer 4. IP is layer 3. Other socket protocols are layer 7 or an implementation of U

Sockets, TCP sockets, are TCP packets in a stream of a given format. TCP is layer 4. IP is layer 3. Other socket protocols are layer 7 or an implementation of UDP. That being said there is no bypassing of NAT, but you can tunnel through it provided an open connection from within the network. For example HTTP cannot connect to a computer inside a NAT network but it can send a response to a request from inside that network. Most P2P services make use of a central server to connect users no differently from instant messaging, and thus these services are generally considered a backdoor into a network. BitTorrent is different because it makes use of two protocols doing different things simultaneously.

the8472 6y ago
> That being said there is no bypassing of NAT There are several. https://en.wikipedia.org/wiki/NAT_traversal https://en.wikipedia.org/wiki/NAT_traversal The approaches don't always work, but often are sufficient for consumer grade routers. > For example HTTP cannot connect to a computer inside a NAT network but it can send a response to a request from inside that network. Well yeah, that's HTTP. It's a client-server protocol. There is no coordination in connection setup. And it's TCP. It's not designed to do the necessary gymnastics to establish incoming connections through a NAT. So HTTP being HTTP is not an argument for NAT traversal being impossible. a) it's much easier with UDP where you can multiplex incoming and outgoing traffic over a single socket and it'll work for any remote peer as long as your UDP NAT uses EIMs.