Function Get-TCPResponse {
<# Author:fuhj(powershell#live.cn ,http://fuhaijun.com)
        .SYNOPSIS
            Tests TCP port of remote or local system and returns a response header
            if applicable
        .DESCRIPTION
            Tests TCP port of remote or local system and returns a response header
            if applicable
            If server has no default response, then Response property will be NULL
        .PARAMETER Computername
            Local or remote system to test connection
        .PARAMETER Port
            TCP Port to connect to
        .PARAMETER TCPTimeout
            Time until connection should abort
        .EXAMPLE
        Get-TCPResponse -Computername pop.126.com -Port 110

        Computername : pop.126.com
        Port         : 110
        IsOpen       : True
        Response     : +OK Welcome to coremail Mail Pop3 Server (126coms[75c606d72bf436dfbce6.....])

        Description
        -----------
        Checks port 110 of an mail server and displays header response.
    #>
    [OutputType(‘Net.TCPResponse‘)]
    [cmdletbinding()]
    Param (
        [parameter(ValueFromPipeline,ValueFromPipelineByPropertyName)]
        [Alias(‘__Server‘,‘IPAddress‘,‘IP‘,‘domain‘)]
        [string[]]$Computername = $env:Computername,
        [int[]]$Port = 25,
        [int]$TCPTimeout = 1000
    )
    Process {
        ForEach ($Computer in $Computername) {
            ForEach ($_port in $Port) {
                $stringBuilder = New-Object Text.StringBuilder
                $tcpClient = New-Object System.Net.Sockets.TCPClient
                $connect = $tcpClient.BeginConnect($Computer,$_port,$null,$null)
                $wait = $connect.AsyncWaitHandle.WaitOne($TCPtimeout,$false)
                If (-NOT $wait) {
                    $object = [pscustomobject] @{
                        Computername = $Computer
                        Port = $_Port
                        IsOpen = $False
                        Response = $Null
                    }
                } Else {
                    While ($True) {
                        #Let buffer
                        Start-Sleep -Milliseconds 1000
                        Write-Verbose "Bytes available: $($tcpClient.Available)"
                        If ([int64]$tcpClient.Available -gt 0) {
                            $stream = $TcpClient.GetStream()
                            $bindResponseBuffer = New-Object Byte[] -ArgumentList $tcpClient.Available
                            [Int]$response = $stream.Read($bindResponseBuffer, 0, $bindResponseBuffer.count)
                            $Null = $stringBuilder.Append(($bindResponseBuffer | ForEach {[char][int]$_}) -join ‘‘)
                        } Else {
                            Break
                        }
                    }
                    $object = [pscustomobject] @{
                        Computername = $Computer
                        Port = $_Port
                        IsOpen = $True
                        Response = $stringBuilder.Tostring()
                    }
                }
                $object.pstypenames.insert(0,‘Net.TCPResponse‘)
                Write-Output $object
                If ($Stream) {
                    $stream.Close()
                    $stream.Dispose()
                }
                $tcpClient.Close()
                $tcpClient.Dispose()
            }
        }
    }
}