PowerShell uses the following commands to open a socket on a specific port via System.NET:

$endpoint = new-object System.Net.IPEndpoint([ipaddress]::any,80)
$listener = new-object System.Net.Sockets.TcpListener $endpoint
$listener.start()
$data = $listener.AcceptTcpClient()

The commands can be used for simulating a network service, as an example to test the network connection before the actual network service is installed, see also: PING with Port - Windows cmd | PowerShell: Test-Netconnection