A friend and I are working on a project where we're required to build a reliable UDPclient/server using VB.Net. We have things working well, but one thing that still eludes us is how to dynamically allocate a (byte) buffer for the incoming data. Right now we have to hard code a maximum value/MTU (or use a really large buffer size and r...
I made two console app: Broadcasting listener and UDP writer (for practice only). Each run on different machine over the internet. Broadcasting listener: INADDR_ANY, port 5555 Udp writer: Enabled Broadcasting (setsockopt, SO_BROADCAST) Case: The writer send some datagrams to listener server (ip: 113.169.123.138). Listener can r...
I've this little script which does it's job pretty well but sometimes it tends to fail. It fails in 2 cases: with error send: Cannot determine peer address at ./tcp-new.pl line 52 with no output or anything, it just fails to deliver what it got to connected Tcp Client. Usually it happens after I disconnect from server, go home and con...
Hello all. Suppose a client sends a number of datagrams to a server through my application. If my application on the server side stops working and cannot receive any datagrams, but the client still continues to send more data grams to the server through UDP protocol, where are those datagrams going? Will they stay in the server's OS dat...
Upon receiving UDP packets from nmap (port scanner), UDP socket that were open by ivrworks (v4) is being closed without any notification. Has anyone encountered such a problem ...
hello friends i have created a UDP chatting program through which the clients can communicate over LAN. I have created a genaralized program i.e. I run the same code with different port nos. and IP address when on LAN My problem is that This code below works fine on localhost but when i try to connect two machines this code doesnt work...
We are developing a application to recieve UDP broadcast from a third party application. Wireshark shows packets of 512 bytes. Each packet have header information. Below is 8 bytes as wireshark shows 01 00 5E 01 02 05 00 11 I have created a small consol based application C# to listen on that specific port. Below is what i am geeting ...
Hello all Image that PC1 and PC2 are trying to communicate via UDP. PC1 is behind a router and PC2 is not. PC1 sends out a UDP datagram to PC2. PC2 can of course receive. Then PC2 sends back a UDP datagram to PC1. We know PC1 can receive too, even if there is a router. The router will record the data channel (I do not want to use "...
I have a simple UDP client server written in C++ on Ubuntu 9.10 where the client sends a set to the server. How can I check how much time s it taking to sent it. I need to find the time from start of transfer to end. Supposing my server and client are on the same machine then can I somehow save the system time and find the difference or...
I want to measure message latency and throughput for both TCP and UDP using C sockets. I am writing a client.c and server.c (Question 1: Do I have to?) that run on different servers to accomplish this. I have to take several measurements using different packet sizes and multiple trials and plot my results. For message latency: Send a pa...
Speed, optimization, and scalability are the typical comparisons between the Udp and Tcp protocols. Tcp touts reliability with the disadvantage of a little extra overhead, but speed is good to excellent. Once a Tcp socket is instanced, keeping the socket open requires some overhead. But compared to the oft described burdens of Udp, which...
Hi! I am running a function: @socket_recvfrom($this->socket, $buf, 8192, 0, $from, $port); but this returns an error saying: socket_recvfrom(): unable to recvfrom [0]: The operation completed successfully. Anyone who has an idèa about this? What does this mean? OS: Windows PHP: 5.3 Morten ...
I have a written a very simple UDP Server using Netty - it quite happily binds itself and accepts messages, but I can'y figure out how to unbind it. Am I missing something, or does Netty not expose the necessary APIs to unbind a server? Edit Here is the code I am using to bind the server: DatagramChannelFactory f = new NioDatagramCha...
Hi All, I am implementing a kind of IP finder for a particular type of network multimedia device. I want to find out all the alive devices of that type in the LAN, with their IP address and other details. The device has its own way of device discovery. It works as follows: A client sends a broadcast request over the LAN via UDP. Th...
I have to connect to a remote server via UDP and send a predetermined message to it in order to get a message back. I had first tried this in TCP and it worked but in UDP after I send the message and listen for the reply in recvfrom() I get nothing. Can anyone tell me what might be the problem here. if ((bytes_sent = sendto(sockfd, UDP_...
Hi, I'm working in a tile-based MMORPG and I have a problem. Each user has a fixed position (one tile) all the time, so the rest of the users can see him there, and cannot move to that tile. So there is only one object or user in each tile. If a user becomes invisible, the rest of the users can't see him, but they still unable to move ...
Hello everyone. I create a module in kernel space that send a UPD segment using socket RAW, but my problem is read the UDP segment from kernel space. I can read the UDP segment from user space, but when I prove to use "sock_recvmsg" from kernel space, I obtain as result -512 Please, help me! ...
i need to send some data to a remote server via UDP in a particular port and get receive a response from it. However, it is blocking and I get not response. I needed to check if the addrinfo value that I get from the getaddrinfo(SERVER_NAME, port, &hints, &servinfo) is correct or not. how do i get the ip address and port number from this...
i am trying to send a string HI to a server over UDP in a particular port and trying to receive a response. however, after i try to get the response using recvfrom() i was stuck in blocking state. i tried using connected udp but i got Error receiving in UDP: Connection refused what could be the reasons for this. the server i not i...
I've been having problems with a third-party application that uses UDP broadcasts to configure some propitiatory networked hardware and I think I've worked out what's going on. It seems that all outgoing broadcast packets are being lost because of bunch of entries in my routing table that route broadcast packets to a non-existent link-lo...