Sockets and using them...

[Era Scarecrow via Digitalmars-d-learn]

On Sunday, 6 November 2016 at 09:51:41 UTC, sarn wrote:
> It sounds like you want to do the same thing: design a protocol 
> that includes some kind of message that's agreed to mean, "Yo, 
> make a new connection on this port."  Basically, any 
> off-the-shelf textbook on network protocol design will help you.
>
> <snip>
>
> Quirks of different NAT implementations cause huge pain to 
> everyone who tries to deploy a peer-to-peer system.

  Yeah, I was hoping it would be 'redirect to this port instead' 
so you wouldn't have to make a new connection. With port 
forwarding and other issues involved, I can see a big problem. 
Once you are using a port I'm pretty sure it will be locked 
(although if multiple can share the same port, I'd be fine with 
that too, as long as I know what IP address it came from).

  I suppose I can simply write it and try to get it working...