networking

How to do a true Java ping from Windows?

I have a device on a network that I am attempting to ping through my Java program. Through my windows command prompt, I can ping the device address fine and do a tracert on the address fine. Online, I have seen that in order to do a ping through Java you have to do the following: InetAddress.getByName(address).isReachable(timeout); B...

What is the Lua equivalent of Twisted Python, Eventmachine for Ruby, NIO for Java, etc.?

What is the Lua equivalent of Twisted Python, Eventmachine for Ruby, NIO for Java, etc.? If there is none, how does one do non-blocking event-based network I/O? In general, how does one solve the C10K problem in Lua? Thanks! ...

Connection to embedded device with Windows and .Net

I am building a .net application(xp, vista, 7) that will communicate with an embedded device. I will be able to connect via IP, serial port and modem. Question: Should I allow some type of open connection within my application that will allow me to connect to the device through some other channels that may be set up in the operating syst...

Possible to compress SQL Server network traffic?

I have a .NET client that needs to connect to a remote SQL Server over the WAN, is it possible to compress SQL traffic between the client and the server? I am using .NET 3.5 and SQL Server 2005 and greater. ...

Should I close sockets from both ends?

I have the following problem. My client program monitor for availability of server in the local network (using Bonjour, but it does not rally mater). As soon as a server is "noticed" by the client application, the client tries to create a socket: Socket(serverIP,serverPort);. At some point the client can loose the server (Bonjour says t...

Peer to peer over 3G

Hey I'm trying to get a CFStream connection going over 3G. I can get it working over wifi using the host name, but when I try to connect directly to the ip address it fails. Is there a guide out there on how to connect over 3G? Thanks ASH ...

Can I close and reopen a socket?

I learned an example of usage of sockets. In this example a client sends a request to a server to open a socket and then the server (listening to a specific port) opens a socket and everything is fine, socket is "opened" from both sides (client and server). But it is still not clear to me how flexible is this stuff. For example, is it p...

Theoretical minimum round-trip-time for a packet to travel over/under the North Atlantic Sea?

I'm doing some performance tuning and capacity planning for a low-latency application and have the following question: What is the theoretical minimum round-trip time for a packet sent between a host in London and one in New York connected via optical fiber? ...

Use UdpClient with IPv4 and IPv6?

A little while ago I created a class to deal with my LAN networking programs. I recently upgraded one of my laptops to windows 7 and relized that windows 7 (or at least the way I have it set up) only supports IPv6, but my desktop is still back in the Windows xp days, and only uses IPv4. The class I created uses the UdpClient class, and...

Does Socket open another thread? Does it return something?

In the client application I call new Socket(serverIP,serverPort). As a result the client application sends a request to the server application to open a socket. Does it start a new thread? I mean which of the following is true? Client application sends a request and immediately starts to execute following commands (not waiting for the ...

How can I force the server socket to re-accept a request from a client?

For those who do not want to read a long question here is a short version: A server has an opened socket for a client. The server gets a request to open a socket from the same client-IP and client-port. I want to fore the server not to refuse such a request but to close the old socket and open a new one. How can I do ti? And here is...

Why do sockets not die when server dies? Why does a socket die when server is alive?

I try to play with sockets a bit. For that I wrote very simple "client" and "server" applications. Client: import java.net.*; public class client { public static void main(String[] args) throws Exception { InetAddress localhost = InetAddress.getLocalHost(); System.out.println("before"); Socket clientSideSocket = null;...

How do I ping a server in J2ME / BlackBerry?

How do I ping a server in J2ME / BlackBerry using java? This seems basic, but I can't find it in the javadocs. Thanks. ...

When should I send QUIT to SMTP server? and how long should I keep a session?

I am programming a smtp sender to send large number of distinct emails (not spam). As there are many destination addresses which are from common provider like hotmail.com/gmail.com. I would like to pool the TCP connections in order to reuse the session. Is this a good practise? Or should I disconnect and connect to send distinct mails in...

What is the best way to communicate with Bonjour?

There is a nice method provided by Bonjour: DNSSD.browse("_killerapp._tcp", this);. As the first argument of this method I give type of service which potentially can be available in the network, and as the second argument I give a "callback object". The considered method "browse" for the services of the indicated type (first argument). ...

Conditional deserialization

I am still not sure whether the title of my question is correct and it most probably is not. However I have spent some time searching both the net and stackoverflow and I can not find a good description of the issue I am facing. Basically what I want to achieve is the ability to read some raw bytes and based on the value of some of them...

Python for a hobbyist programmer ( a few questions)

I'm a hobbyist programmer (only in TI-Basic before now), and after much, much, much debating with myself, I've decided to learn Python. I don't have a ton of free time to teach myself a hundred languages and all programming I do will be for personal use or for distributing to people who need them, so I decided that I needed one good, str...

Verfiying the network connection using Qt 4.4

Hi, I have an application which runs a tool that requires network connection. Now my aim is to check whether the user has a network connection, if he don't have one, i can straight away display an error without proceeding further. If he has, he can continue working with my application. So my basic need is to check whether the user has a ...

TCP/IP RST being sent differently in different browsers.

On Mac OS X (10.6), if I start a YouTube video download and pull the Ethernet cable for 5 or so seconds, then plug it back in, I get varying results depending on the browser. With Opera and Chrome, after I plug the cable back in the video continues to load. But with Safari and Firefox, it never does. Using Wireshark to look at the traff...

WCF - (Custom) binary serialisation.

I want to be able to query my database over the web, and I am wanting to use a WCF service to handle the requests and results. The problem is that due to the amount of data that can potentially be returned from these queries, I'm worried about how these results will be serialised over the network. For example, I can imagine the XML seria...