I was under the impression that in Java, a Thread will pause and give other threads a chance to do some work during blocking I/O operations ( like Socket.read() or DataGramsocket.receive() ). For some reason in my multi threaded network application, a call to receive() is causing all my other threads to starve ( the thread that called re...
I am coding a very simple DHCP client in C. I have trouble deciding whether it should use UDP or TCP, what basic commands should it support. I think it should be able to get at least DNS, SMTP, POP3 server information from server. What else do I need to know? Is there a basic DHCP C implementation available which can help? ...
I am working to integrate data from an external web service in the client side of my appliction. Someone asked me to test the condition when the service is unavailable or down. Anyone have any tips on how to block this site temporarily while we run the test to see how the service degrades? For those curious we are testing against Virtu...
Hi, can anyone tell me how to check if a Windows CE 4.2 device is currently connected to the Internet, i.e. how to get the RAS connection status (we are using RAS autodial)? I can of course do something like a DNS query, but I certainly would like to do this without actually generating data traffic ... or is this the only way? I am stil...
HI, Let us say that there are 10 packets 1-10 and the 6th Packet gets dropped because of a network fault. Does TCP resend's all packets from 6-10 or just 6th ? ...
What could be good list of failure scenaros for testing a reliable udp layer? I have thought of the below cases: - Drop Data packets - Drop ACK, NAK Packets - Send packets in out of sequence. - Drop intial hand shaking packets - Drop close / shutdown packets - Duplicate packets Please help in identifying other cases that reliable udp ne...
does anyone knows a GUI tool for netwotk ACL configuration?.The uesr will give some inputs via GUI then this should be transferred into ACL configuration. The device is a CISCO router.. ...
Is there a way for flash to detect a user's bandwidth, and depending the size of bandwidth, stop loading, or continue with the load? Now that I'm thinking about it, this would probably be a javascript detection script and if the bandwidth is high, load .swf, if not load a .jpg? ...
Hi, Just a technical question - Can two or more SNMP agents be run on the same port (on the same machine)? My first instinct would be no since host:port identifies an instance of an application but I'm not sure. Thank you! ...
I require socket-like local IPC. I used named pipes and overlapped IO on windows and I want to rewrite the application to boost::ASIO so that it can use UNIX domain sockets as well. I've recently reviewed parts of the libevent library and I know it only supports socket() and select() for windows in the 1.4 version. As overlapped IO is v...
Where can I find benchmarks on different networking architectures? I am playing with sockets / threads / forks and I'd like to know what the best is. I was thinking there has got to be a place where someone has already spelled out all the pros and cons of different architectures for a socket service, listed benchmarks with code that run...
I'm trying to play around with UPnP. Specifically, I'm trying to browse the content library of a PS3 Media Server. I tried upnp.dll (a COM library that ships with windows) and found it easy to use. I can discover devices and look at their services pretty easily, however it throws an exception when trying to access the services of the m...
How do my program on Pocket PC (.Net CF v3.5) can communicate with program on my Desktop (.Net application) ? The Pocket PC is in cradle, connected via usb. Update: I know how to use socket to open TCP or send datagrams. I know how to use TcpClient/TcpListener. I just don't know how to give configuration for opening sockets for this s...
How can I disconnect any process from the Internet? PID process and IP (local / remote) are known. ...
Is there any field/option/anything that I can put in a TCP packet (be it a syn or an ack or just plain data) that I can be sure will be returned by the other end intact? For eg. I want to "tag" a particular connection (src, srcport, dst, dstport) with a number that I can always read from a packet belonging to that connection. That means...
import java.net.*; import java.io.IOException; import javax.swing.*; import java.awt.*; import java.awt.event.*; public class PortScanner { public static void main(String[] args) { InetAddress ia=null; String host=null; try { host=JOptionPane.showInputDialog("Enter the Host name to scan:\n example: xx...
In linux, you can get the following statistics with netstat: Active Internet connections (including servers) Proto Recv-Q Send-Q Local Address Foreign Address (state) tcp4 0 0 192.168.1.136.58519 72.47.210.69.80 LAST_ACK tcp4 37 0 192.168.1.136.57059 174.129.27.181.443 CLOSE_WAIT ...
I've got a couple questions about sending images over. How do I handle different types of files, jpeg, png, etc. If the file is large, I ave to use sequence numbers... but I don't know how to stop recving if I do not know the number of sequence numbers. My knowledge of transfering images / files is next to none. I have never programme...
I'm not interested in a hardware solution, I want to know about software that may "read" modulated signal received trough the power supply - some sort of a low-level driver that would access the power signal in a convenient place and demodulate it. Is there a way to receive signal from the computer's power supply? I'm interested in an A...
Once a Tcp/Ip connection has been established between two applications running on the same computer, using the localhost loop back is there any real possibility of losing that connection? Or is it possible to make the assumption that such a connection loss is as rare as a blue screen event, and treat it in a very exceptional manner. Ass...