darkserver2

try
{
    $clientList = New-Object System.Collections.ArrayList
    $server = [System.Net.Sockets.TcpListener]12345
    $Server.Start()

    while ($server.Active -eq $True)
    {
        if($server.Pending() -eq $False)
            {
                Update_ClientList($clientList)
            }
            else
            {
                $client = $server.AcceptTcpClient()
            $clientList.Add($client)
            }
    }
}
catch
{
    # Code to handle errors here
}

function Update_ClientList
{
    param ([System.Collections.ArrayList] $ClientList)

    foreach ($client in $ClientList)
    {
        if ($client.Available -gt 0)
        {
            # Data is available on this client
            # Code to read/process the data goes here
        }
    }
}