Socket.Receive Is Dropping The Last Byte Of Every Packet
Nov 11, 2010
I am having trouble with a socket client application written in vb.net using Visual Studio 2005. The client connects to a C language socket server that is running on OpenVMS. The problem that I have is that when the server sends a packet, the client does not receive the last byte (of every packet!). I can dump the packets on the network and the data is all there. My current solution is to keep my socket messages short (247 bytes) and send one extra byte past the end of my data.
I would like to include more information in my messages and I cannot find a way to make this work. If I knew 100% how long the packets will be on the network, I could work around this by including an extra byte in just the right places. However, I don't want to make any assumptions about the length of the packets.
Here is a sample of my client receive code:
Private Sub ReceiveMsg()
Dim nTotalBytes As Integer
Dim nNumBytes As Integer
[Code]....
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Jul 4, 2011
I'm writing a program which uses sockets, Now the issue I'm having is, If the packet received is over a certain size, the socket then fails to receive anymore packets/data after it.
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Feb 22, 2009
I am trying to intercept connections on port 2302 that is being used by a game. I was think about using something along the lines of
#Region " Imports "
Imports System
Imports System.IO
Imports System.Windows.Forms
[code]....
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Dec 8, 2009
I just converted the following code from c# to vb.net. It is functional and works correctly with my company's firmware/devices. My next challenge. Previous serialport code used much more readable structs which where then converted (after building a packet) into byte() automatically as part of the serialport encoding. (this is my understanding)How could I
1. morph byte arrays 'ToSocket' and 'ToMTP' below into structs and
2. convert into byte array for Socket.BeginSend(byte(),.....) to stream out to remote devices?
Imports System.ComponentModel
Imports System.Text
Imports System.Net.Sockets
[Code]....
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Oct 15, 2011
Below is my code, but when i send the message thru client socket i receive Specified argument was out of the range of valid values. Parameter name: size
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim serverStream As NetworkStream = clientSocket.GetStream()
Dim outStream As Byte() = _
System.Text.Encoding.ASCII.GetBytes("0800822000000000000004000000000000000920092126012345001")
[CODE]...
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Feb 2, 2011
I have a packet that I need to send to a client with an ID of 255. I've had no problems sending packets with IDs of 0, 1, and 2. The ID has to be 255. For some reason, after the translation has happened, both me with my server, and the client, get "63" for any Id greater than 127.
This is the code I am using:
Console.WriteLine(Asc(System.Text.ASCIIEncoding.ASCII.GetString(System.Text.ASCIIEncoding.ASCII.GetBytes(Chr("255")))))
Now, This is an overly complicated version of what the server does. You may consider this a bit unnecessary but the inverse functions performed are for your viewing reasons only.
Where it says "255" is the Packet Id I need sent in the format above. As I said, anything larger than 127 returns "63".
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Sep 14, 2008
What Visual Basic code can be used to assemble and send a raw packet, and receive response packets? I looked on MSDN and I couldn't find any documentation for anything used to send a packet.
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Mar 7, 2012
basically I'm sending and receiving both images, strings and files over a client/server connection. I can easily use a protocol for string commands but I cannot distinguish between the incoming data [if data is image or whatever and then follow onward instructions].So how do I make a packet using Dim buffer as byte()?
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Aug 2, 2010
I've been using some code which I found on the net, and have noticed that the first byte is never recieved. Annoyingly, this contains the MAC addresses, which is the bit I want. Below is the relevant snippits:
Public Sub [Start]()
If m_Socket Is Nothing Then
Try
[Code].....
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May 25, 2009
I am sending data to server via TCP IP Connection. I am using a continuous loop at the server end - that accepts new clients and while streams can be read, it reads data stream.
The data is sent from the client with 2 leading bytes of data that represent the size of the packet of data sent and type of data.
My question is: how do I retrieve the size of the data packet and then check that this amount of data has been retrieved?
[Code].....
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May 25, 2009
I am sending data to server via TCP IP Connection. I am using a continuous loop at the server end - that accepts new clients and while streams can be read, it reads data stream.
The data is sent from the client with 2 leading bytes of data that represent the size of the packet of data sent and type of data.
My question is: how do I retrieve the size of the data packet and then check that this amount of data has been retrieved?[code]...
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Feb 6, 2011
I'm working with the Minecraft Server To Client protocol documentation for a server I am making.It says the packet is 18+ bytes, but I can't seem to figure out what each byte is for.
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Feb 29, 2012
I have these following lines to send bytes using socket
Dim server As New Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp)
Dim myIp As IPAddress = IPAddress.Parse("myIP")
Dim ip As New IPEndPoint(myIp, Int32.Parse("myPort"))
[Code]....
As in the code, I am supposed to retrieved "Halo". Instead I keep receiving sth like "[]".
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Jan 5, 2012
I coded a small tcp server/client software implementing the async methods of the socket object. In order to keep track and control of the transfered data on both sides, I decided to wrap the bytes to be transfered into small 65 000 bytes packets, sent one after each other, in varying order.In most cases, it works perfectly, and it is impressively fast. However, when I want to transfer larger data than my usual requests, say like a dozen megabytes, crippling problems start to appear, out of shit.Effectively, it seems that somehow when executed without pauses, the server sends the packets too fast, or that the client receives it too slowly. However, if I put the SendAsync method's thread to sleep for like 100ms before sendingthe next packet, everything arrives without problem on the client.[code]
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Feb 19, 2012
My client program gets stuck on NetworkStream.Read even though the server is reporting it's sending the message. The client and server are running on the same computer.Full server code (console application)
Imports System.Net.Sockets
Imports System.Text
Module Module1
Sub Main()
[Code]...
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Mar 24, 2012
I converted some codes from python to VB 2010. My aim is sending query data to multicast IP and get the response. My query data receiving from device which is connected to my LAN. Also the device responding my query and my PC receiving the responce but at this point the VB program freezing.getting response data and printing to console without freezing.
This is the code list;
Imports System.Net
Imports System.Net.Sockets
Imports System.Text
[code]....
Here is the Wire Shark (Network Protocol Anlyzer) screen shots; My computer IP is : 192.168.0.11 and device's IP is : 192.168.0.10.
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Jul 29, 2009
I am trying to implement SMPP protocol in vb. I am sucessfull in send and receiving packets using sockets. Now I would like to decentralize the functions of my program. I want to implement two programs one for sending and another for receiving using a single socket. I want to receive data through the same socket that was created in another process(i.e., the first program).
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Apr 18, 2011
I need to include in my application that can receive connections from a client( or two).I am thinking, that I would like to have the clients send a "TelegramID" so that I may now how to process the code.Following the "TelegramID" would be a structure that would need to be processed.So far, I can use a single client and send just plain text but need some direction for my end goals.
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Sep 3, 2010
I've looked through a lot of snippets online and I see a lot of things similar to
Dim bytes(tcpClient.ReceiveBufferSize) As Byte
networkStream.Read(bytes, 0, CInt(tcpClient.ReceiveBufferSize))
but what I am unsure of when to call such a thing? How do I know when there is data to receive...in visual basic 6 with winsock, there was a specific routine which was called upon data arrival, but I see nothing of the sort for vbNet.
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Mar 6, 2009
I realize this is a broad question, but how do I recieve / send packets. I know what packets I need to send and what Im going to recieve, but I dont know how to send / recieve them.
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Nov 28, 2009
While using the Socket.Receive method to receive messages through network, you should define a variable as the buffer and you have to specify the length like this: Code: Dim _ReadBuffer As Byte() = New Byte(LENGTH) {} My question is: What is the bad thing about increasing the length of this variable even if the received messages are sometimes shorter? (i.e. if some body let it 10000).
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Aug 26, 2010
I have created a Client that can send and receive data via TCP sockets. The objects stored on the serverside are the *exact* same object used for the client. They use the same send and receive protocols.
Now, when i send a string from the server to the client , it does precisely what it should do. However when I send a string to the server.... I do receive the string as an equal length of NULL characters. I run the server and client locally.
Basicly what can influence the behaviour between two completely identical objects performing the exact same task? I wonder if there is some socketflag issue if the TCPlistener.accept function returns a completely different setup then the one I R used to.
(if it is of any interest, the send protocol is asynchronious)
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Aug 28, 2009
I am trying to communicate with an external device and i am trying to send a byte array to the external device via sockets but i am always getting a response the message size is too small so i am not sure what i have done wrong. Between the data type there should be no alignment present and all numbers are represented in little endian format. The char array is not null terminated as mentioned in the protocol specifications.I have to send data based on a struct that embeds 2 other struct. So here's my vb.net code for the struct used to convert to byte array and the sending part.[code]
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Sep 21, 2010
I've inherited a tested function that processes incoming data from a .NET Serial Port. (Dim RXBuffer as string = serialport1.ReadExisting) I've written a different part of the application that processes a byte array as received from an asynchronous .NET socket.
Is there a way I can convert the byte array into a string as if it arrived from the serial port?
I would prefer to rewrite a very long 'if statement' into byte array functions syntax that look like:
dim b as boolean = IsBitSet(state_buffer(i), j) 'rather than:
dim b as boolean = (Asc(Mid(RXPacket.Pdu, CInt((i - (i Mod 8)) / 8) + 1, 1)) And CInt(2 ^ (i Mod 8))) > 0
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Aug 29, 2009
I am trying to communicate with an external device and i am trying to send a byte array to the external device via sockets but i am always getting a response the message size is too small so i am not sure what i have done wrong. Between the data type there should be no alignment present and all numbers are represented in little endian format. The char array is not null terminated as mentioned in the protocol specifications.
I have to send data based on a struct that embeds 2 other struct. So here's my vb.net code for the struct used to convert to byte array and the sending part.
Public Structure MESSAGETYPE_OIP_Login
Dim Header() As COMMANDHEADER
Dim UserName() As PSTRING
[Code]....
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Aug 7, 2010
Why does C# define Byte+Byte=Int32 instead of Byte+Byte=Byte like VB?
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May 21, 2011
I wrote a Socket Client which will send the Socket Server some data and get some response from Server. This process will be running once in every 2 seconds.
Now what I need to know is How we can identify the connection lost between Server and Client?
I need this to be implemented in the Client side. If there is no connection then Client should automatically close the connection. Once the connection with the server is available in the next attempt it should connect automatically.
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Oct 15, 2009
I'm running this on Microsoft Visual Basic 2008 I want to make a program with 2 forms, one with buttons, the other that will just hold picture boxes, which are created when those buttons are clicked. Once those picture boxes are placed on the second form, I want to be able to drag and drop them to move them anywhere on that second form.
I have it "working" as of right now, but it's really glitchy. Almost as if it can't keep up with my mouse movement. But I'm not moving THAT fast so I can only assume that something is wrong.The buttons work so I won't post that code here but the following code is for the second form and what I'm using to control the picture boxes.
Public Class Form2
Private counter As Integer
Private boxCounter As Integer
Private list As New ArrayList
[code]....
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Sep 22, 2009
I am in a visual basics 2008 class for my MIS degree. This is the beginners class. We were instructed to build a program that calculates a score average. However, we get extra credit if we figure out how to drop the lowest test score. I do not know how to do this. The teacher won't help with the extra credit. I will post my code.
[Code]...
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Jun 22, 2009
Right now I have checkboxes on my form, and depending on what check box I check, the value of it gets put into a text box. So if I check "Right Eye", the texb ox below it gets "Right Eye" placed there.
I would like to do away with the check boxes and instead have a new form pop up with a list of words that gets populated from a table. Is it possible to be able to drag and drop these words into a text box? I guess I could use a List Box control for that but I'm unsure how to implement drag and drop. Maybe be able to multi-select words and then drag them all to a certain text box.
I'd like to have give the user the option of adding and deleting words from that form as they see fit, so could I just let VS do that for me by dragging the datasource onto the form and have it create a bindingnavigator or should I do it myself?
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