UDP is secure and TCP isn't?

[Info]

I noticed that when "spamming" data to the server via TCP (no delay between each send function), the server gets the data all wrong. (this didn't only happen to me in AutoIt)

So I tried doing the same thing with a UDP connection and the data came out fine.

Here's 2 examples of server-client scripts that spam an "abc" string to the server, which then displays the string in a tooltip.

TCP server

TCPStartup()
OnAutoItExitRegister("clean")

Func clean()
TCPShutdown()
EndFunc

$list = TCPListen("127.0.0.1", 8075)

While 1
$accept = TCPAccept($list)
if $accept >= 0 Then
While 1
$recv = TCPRecv($accept, 100)
If Not @error And $recv <> "" Then
ToolTip($recv)
$recv = ""
EndIf
WEnd
EndIf
WEnd

TCP client

TCPStartup()
OnAutoItExitRegister("clean")

Func clean()
TCPShutdown()
EndFunc

$con = TCPConnect("127.0.0.1", 8075)
If @error Then Exit

While 1
TCPSend($con, "abc")
WEnd

UDP server

UDPStartup()

; Register the cleanup function.
OnAutoItExitRegister("Cleanup")

; Bind to a SOCKET
;==============================================
Local $socket = UDPBind("127.0.0.1", 8075)
If @error <> 0 Then Exit

While 1
Local $data = UDPRecv($socket, 50)
If $data <> "" Then
ToolTip($data)
EndIf
WEnd

Func Cleanup()
UDPCloseSocket($socket)
UDPShutdown()
EndFunc ;==>Cleanup

UDP client

UDPStartup()

; Register the cleanup function.
OnAutoItExitRegister("Cleanup")

; Bind to a SOCKET
;==============================================
Local $socket = UDPOpen("127.0.0.1", 8075)
If @error <> 0 Then Exit

$i = 1000

While 1
UDPSend($socket, "abc")
WEnd

Func Cleanup()
UDPCloseSocket($socket)
UDPShutdown()
EndFunc ;==>Cleanup

Result in the TCP server:

Result in the UDP server:

Isn't it supposed to be the other way around?

Why do I get "secured" data in the UDP connection and wrong data in the TCP connection?

[guinness]

Adding Sleep(20) in both TCP examples (even UDP) will give time for the TCPRecv function to breath.

[Info]

Adding Sleep(20) in both TCP examples (even UDP) will give time for the TCPRecv function to breath.

But what if the server and the client are supposed to receive and send information in such short delays? (video games softwares, etc...)

Also, I did what you said in the TCP code and it still receives wrong strings.

[guinness]

I tried it and it worked for me. Search Trac, as I believe there is a ticket floating around about TCPRecv.

[DicatoroftheUSA]

I would tell you a joke about UDP, but you might not get it.

TCP, has more over head, and it needs time to coordinate with the sender whether or not the packet actually was received. But that should be handled by the function. It may be worth it to you to run wireshark on both ends to see what exactly is happening.

As far as being secure, the term at least in computing, it usually refers to the ability to withstand attacks or theft. A better title keyword might be reliable?

Edited January 16, 2013 by DicatoroftheUSA

[Info]

I would tell you a joke about UDP, but you might not get it.

Please do tell

[JohnOne]

Please do tell

PMSL

[JohnQSmith]

Please do tell

OK... explanation time.

TCP guarantees that a message will arrive. The server sends a message and then waits for the client to send back a message saying that it was received. If the server doesn't receive an "I got it" message from the client, the server resends the message and the process repeats up to a set number of attempts before failing.

UDP doesn't guarantee the message will arrive. The server sends the message and then goes on about it's business without worrying about whether or not the client received it.

So, in summation, "I would tell you a joke about UDP, but you might not get it" was the joke itself.

@JohnOne: Yeah, me too, but I had to try to help.

[guinness]

Very witty DicatoroftheUSA.

[JohnOne]

OK... explanation time.

Never, ever explain your gags.

Ever.

If there were a law, it'd be against it.

[Info]

Never, ever explain your gags.

Ever.

If there were a law, it'd be against it.

He just explained the joke don't be an asshole

[guinness]

Hey Info,

Why the aggressive tone? JohnOne wasn't being rude, he was just being playful.

[guinness]

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#region Server
TCPStartup()
OnAutoItExitRegister('Cleanup')

Server()

Func Server()
    Local Const $TCP_RECIEVELEN = 4096
    Local $iListen = TCPListen('127.0.0.1', 8075)
    Local $iAccept = 0, $sPrevious = '', $sTCPRecv = ''

    While 1
        $iAccept = TCPAccept($iListen)
        If $iAccept >= 0 Then
            While 1
                $sTCPRecv = TCPRecv($iAccept, $TCP_RECIEVELEN)
                If $sTCPRecv <> '' And $sTCPRecv <> $sPrevious Then
                    ToolTip($sTCPRecv)
                    ConsoleWrite($sTCPRecv & @CRLF)
                    $sPrevious = $sTCPRecv
                EndIf
            WEnd
        EndIf
    WEnd
EndFunc   ;==>Server

Func Cleanup()
    TCPShutdown()
EndFunc   ;==>Cleanup
#endregion Server

#region Client
TCPStartup()
OnAutoItExitRegister('Cleanup')

Client()

Func Client()
    Local $iCount = 0
    Local $iConnect = TCPConnect('127.0.0.1', 8075)
    If @error = 0 Then
        While 1
            If TCPSend($iConnect, 'Send__' & $iCount) = 0 Then ExitLoop
            $iCount += 1
            Sleep(100)
        WEnd
    EndIf
EndFunc   ;==>Client

Func Cleanup()
    TCPShutdown()
EndFunc   ;==>Cleanup
#endregion Client