Im sending packets through UDP, and want to get the time it takes for the server to receive the packet from the client. Would the best way be by adding a timestamp to the packet the client sends, and then use that time with the server to calculate the actual time it took to receive?
View 39 RepliesIs there a way to extract the value for APPEARANCE_NORMAL from each stamp in a PDF using iTextSharp? I know how to find all the Stamp annotations, but I am unsure how to get APPEARANCE_NORMAL.
View 6 RepliesI have a program which uses TcpClient, the issue I'm having is how do I construct the packets when some of them come in seperate parts. For example, If I receive 5 packets, 2 of them are fine, but the other 3 have come in seperate parts when it's suppose to be a whole packet. How can I handle this?
View 5 RepliesHey there, I thought i would redo my question, How could i send packets in VB to a IP and Port, I'm unsure on how to do this could somebody tell me?
View 4 RepliesEmpty values in byte array at the end of one packet are replaced by beginning values of the next packet sent in TCP connection. How may I avoid this?
View 4 Repliesi try to transfer packets from the PC to the Mobile phone~ my PC is act as a Server and Mobile as a Client. My Mobile is successfully connect to my PC, but when i try to pass a packets from Mobile, it went failed without any error. The Server didn't receive any packets from Mobile. i had test my code on PC to PC and it's work fine. Anyone have this kind of experience?
View 3 RepliesI am writing a program that talks back and forth with an external machine through UDP/IP. I have figured out how to talk to the machine, bu now I need to know how to read the machine's response. I am using the following code:
Dim receiveBytes As [Byte]() = udpClient.Receive(RemoteIpEndPoint)
Dim returnData As String = Encoding.ASCII.GetString(receiveBytes)
TextBox1.Text = returnData
When I break the code down and read receiveBytes, it comes through exactly the way I want it. It is falling apart when it gets encoded and put into a textbox. It just comes out as a "?".
I am trying to receive about 900 packets coming from around 900 different ip's. But for some reason I can't seem to capture them all. The same code in C++ seems to work fine, but when I try to do it and run it through the parser it seems that I only get about 150 - 300 of these packets each time I ask for them.
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Does anyone know of a good example of TCP, in C# or VB.NET?
The problem I have with the majority i've found is that they send data once, receive data once, and end. This isn't a workable example. Even MSDN's example does this.
My main question:
Every example reads incoming data into a buffer (byte array), usually 512 bytes. If two packets are received in a row, how do I know where one packet's data ends and another's begins? What if a single packet has more than 512 bytes of data?
All TCP examples i've found work in a rather procedural way.
I'd like to have something as simple as this:
Code:
Public Sub OnPacket(data As Byte())
End Sub
Can I send and detect individual SYN or FIN packets using VB.NET Sockets or any other process in VB.NET?
View 2 RepliesSince a few months I want to learn how to receive and send packets. Since WinSock doesn't work I think it'll be quite hard to get an easy way to do it.
I want to be able to send and get packets as a client. (TCP) I know that I need System.Net.Sockets, and that's quite everything...
I am on a new topic in VB.NET and I am so confused I don't really even know where to start. It is sending Parsed Packets. This packet below is a login server of a game and I want to know how to send it so it automatically does it.[code]....
View 6 RepliesI made a TCP server which communicates with multiple clients at once, but I can't seem to be able to make them stable. When one of the client sends 100 packets to the server, the server receives only a few of them.Here's the client code in PasteBin. It shows how the client connects to the server and then sends 100 messages in a For loop to the server.And here's how the server handles the connection. I couldn't paste the full source as it's hundreds of lines long so let me know if it's missing any mandatory parts and I'll upload them as well.
View 1 RepliesHere's the code on the sending side of my sockets:
Private Sub Send(ByRef Buffer() As Byte)
Dim obj_StateObject As New StateObject
obj_StateObject.WorkSocket = m_tmpSocket
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Well I need to send a raw packet to a Web Browser Control. The packet is:
"%xt%z%zo%50% . 1000000 . "%""
I need to send it to a flash game but I have no idea how to.
I have been trying to figure out how to use Packet X to Capture Packets from a certain program that uses UDP. Does anyone know how to do so?
View 1 RepliesThe following code waits for data over UDP. I have a test function that sends 1000 packets (datagrams?) of 500 bytes each. Each time I run the test function, the receiver gets only the first few dozen packets but drops the rest. I looked at the incoming network data using Wireshark and I see all 1000 packets are actually received, but just don't make it to may app's code.[code]If I add a small delay after each call to Send, more packets make it through; however since Wireshark says that they were all received anyways, it seems that the problem is in my receive code. I should mention that UdpListen is running on a separate thread.Any idea why I am dropping packets? I also tried UdpClient. BeginReceive/ EndReceive but had the same problem. A second issue that bothers me is the global nature of the receive buffer when using Sockets and I am not sure if I don't process incoming packets quickly enough that the buffer will be overwritten.
Based on the various, somewhat conflicting suggestions from replies to this and other posts, I made some changes to my code. Thanks to all who chimed in various bits; I now get all my packets from dial-up to Fast Ethernet. As you can see, it was my code at fault and not the fact that UDP drops packets (in fact I have not seen more than a tiny percentage of packets being dropped or out of order since my fixes). Differences:
1) Replaced BeginReceive()/EndReceive() with BeginReceiveFrom()/EndReceiveFrom(). By itself this had no notible effect though.
2) Chaining BeginReceiveFrom() calls instead of waiting for the async handle to set. Not sure if any benefit here.
3) Explicitly set the Socket.ReceiveBufferSize to 500000 which is enough for 1 second worth of my data at Fast Ethernet speed. Turns out this is a different buffer than the one passed to BeginReceiveFrom(). This had the biggest benefit.
4) I also modified my send routine to wait a couple of ms after having sent a certain number of bytes to throttle based on expected bandwidth. This had a big benefit for my receiving code even though Wireshark said all my data still made it across even without this delay.
I did NOT end up using a separate processing thread because, as I understand it, each call to BeginReceiveFrom will invoke my callback on a new worker thread. This means that I can have more than one callback running at the same time. It also means that once I call BeginReceiveFrom I have time to do my stuff (as long as I don't take too long and exaust the available worker threads).[code]What is not shown above is the error handling and dealing with UDP data being out of order or missing.I think this handles my issue, but if anybody still sees anything wrong with the above (or something I could do better) I would love to hear about it.
I need to make a packet sniffer that will give me SSL packets. It doesn't need to give me any other information than the body of the packet, the actual data being sent to me. It does not need to differentiate between different IP addresses. And, it doesn't even need to differentiate between things which are and are not SSL packets. Any packets will be fine, it just needs to support SSL packets. The fewer lines of code the better...
View 5 RepliesNow i need to send separate packets from the server to the client.For the client I am using usual Tcp but for the server I am using Winsock Control. [code]...
View 5 RepliesI'm trying to sniff packets from a specific application. I searched around but couldn't find anything useful, but I did hear something about WinPcap. What is WinPcap and how do I use it? Also, is there another way to sniff packets?
View 6 RepliesAt my workplace I have been developing a server/client application which receives on port 8000 and sends on 8001. We do not have any other applications that use these ports, but we do have an application that accesses an SQL database in which part data is stored.
When I am doing testing on the application, if the server were to crash while the client app was sending a packet, could this lost packet cause issues with the network at all?I ask because for some reason we have been receiving connection timeout errors from the application that stores our product data, but we haven't made any changes or started running any new jobs on the network that I am aware of.
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.
View 2 RepliesI have written a simple Server application that transmits an XML string to all connected clients when the user updates/alters a datagridview. When I connect to this server with telnet I can see the correctly formed xml string.
I have also written a client application, which on reception of the Xml string, displays it in a datagridview. But When I look at the xml string it is either missing parts of in the wrong sequence.
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I need a start date, a Total time passed until now, an average time per step, and a estimated time to finished. How can I do that? Also, I can close the application and when start up again I want to get the time counters as the last time, so How can I store that data is normal txt file (I say txt to take advantage of the ini app file which is a txt).
View 1 RepliesI have a webserver and I upload files to my webserver from time to time. I have an ftp account which points to public_html that is main directory.
I though why give full access so I created another ftp account (e.g. test) which points to a specific folder. Now when I try to upload a file using test it fails.
For e.g.
the following code works:
My.Computer.Network.UploadFile("d:ok.txt", "ftp://mysite.com/Test/okay.txt", "main@mysite.com", "mainpw")
- this is because this a/c has access to root folder of website
now following code gives error -
My.Computer.Network.UploadFile("d:ok.txt", "ftp://mysite.com/Test/okay.txt", "test@mysite.com", "testpw")
The remote server returned an error: (550) File unavailable (e.g., file not found, no access).
Well the ftp account test has been given access to a specific folder with the name "Test". So it should at least upload to that folder.
But if I use ftp client (like filezilla) then it works.
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.
View 3 RepliesI am trying to make a program that will stop people on the same network being able to tale if im online by pinging my i.p adress aparantly the only way of doing this is to "drop icmp packets and not reply to them"
dose anyone know how to do this? and can anyone provide me with a basic script that will do this?
I have an ASP.NET application with a SQL Server back end. I am storing all my dates in UTC format and doing the appropriate conversions to the local time zone of the browser viewing it. One of the pages asks for a start date and end date (no times).
I am taking the start date and setting the time to 00:00:00 hours (midnight) and I'm taking the End time and adding a time of 23:59:59, so that the date range covers the whole day. Now what I'm trying to do is do a SQL query to do a search for records in this date range. The problem is, the data in SQL is in UTC time and the user is typing their dates and times in their local date and times. My quickest solution was to convert the date and time to UTC, then search the records. However, by doing this, I am to believe ASP.NET converts the given time and date to UTC based on the server time zone. How can I convert a date and time to UTC time based on the time zone of the user?
im trying to convert a 24hour time input in a textbox into a 12hour format and place the answer inside another textbox 1345 = 01:45 this and also whats the easiest way to block out a number like "1365" (01:65) from being entered/run ?
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how can i do some modification only first time i run the application.i want to set up the folder where is a mdb file, but i want to that only at first launch of application.i select my file with openfiledialog
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