Network Framework Migration Guides

Migration 1: From BSD Sockets to NWConnection

BSD Sockets	NWConnection	Notes
`socket() + connect()`	`NWConnection(host:port:using:) + start()`	Non-blocking by default
`send() / sendto()`	`connection.send(content:completion:)`	Async, returns immediately
`recv() / recvfrom()`	`connection.receive(minimumIncompleteLength:maximumLength:completion:)`	Async, returns immediately
`bind() + listen()`	`NWListener(using:on:)`	Automatic port binding
`accept()`	`listener.newConnectionHandler`	Callback for each connection
`getaddrinfo()`	Let NWConnection handle DNS	Smart resolution with racing
`SCNetworkReachability`	`connection.stateUpdateHandler` waiting state	No race conditions
`setsockopt()`	`NWParameters` configuration	Type-safe options