hi all, After making a tcp connection to a server, I close my linux application and Socket.close() is called. Checking netstat -pant, I see the connection is in TIME_WAIT status. This prevents me from making an immediate connection back to the server since I'm using the same port to connect from. Instead, I have to wait for the conne...
I'm troubleshooting some communications issues and in the network traces I am occasionally coming across TCP sequence errors. One example I've got is: Server to Client: Seq=3174, Len=50 Client to Server: Ack=3224 Server to Client: Seq=3224, Len=50 Client to Server: Ack=3224 Server to Client: Seq=3274, Len=10 Client to Server: Ack=3224,...
I have a simple socket server, that waits for a message and responds. How can I test this? Is there a client app or something that can help me send some data on a specific port to a server, and see the output? Telnet? ...
I have a class that receives data from a socket. What i'm looking for is a pre-existing application for testing sockets. For example I pass configuration data to the app which then fires up and sends a data to my 'receive' socket. It should also output debug information. Ive looked into hercules but I don't believe I can interop with it...
I have written a server that performs non-blocking IO using the Java NIO API. I'm seeing a situation whereby occassionally a client application shuts down abruptly (e.g. due to power loss) and the connection is left open on the server-side. A colleague has encountered the same problem and said he uses heartbeats over the line to detect...
I have a web app which relies on a number of back end services, and I would like to be able to dynamically switch between different instances of these services. So the thinking was to create an intermediate app which listens on some ports and redirects traffic as required. If I was dealing with pure HTTP I would look at doing this with...
We have a system (built in C) in place that performs communication over UDP. Recently we have found a necessity to guarantee delivery of packets. My question is: what would be the minimum additions to a UDP based system to ensure delivery using ack packets? Also, ideally without having to manipulate the packet headers. We have applic...
I've written a socket server which communicates with my actionscript 3 flash game using the Socket class. This is a TCP connection, which I thought would mean that it is 100% sure that the sending message will be received by the server as this is done low-level. So, if it would fail to send it would resend the message. This does seem to...
If I have a large HTTP packet which has been split up into a number of TCP packets, how can I reconstruct them back into a single HTTP packet? Basically, where in the packet do I look to tell when a HTTP packet is starting/ending? I can't seem to see any flags/fields in the TCP header that denote the start or end of the HTTP packet. ...
Why do multiple connections from the same host achieve better throughput than multiple connections from different hosts? I suspect is something kernel-related (Linux) but a confirmation would help a lot. More details I have 1 receiver process, let's call it R. It accepts incoming connections and receives data using select(). I have 3 ...
I use Indy's TIdTCPServer (D2009, Indy 10) to communicate with client applications. In the OnExecute method I create a task and queue it. A worker thread executes the task and puts it in the send queue. The send queue then sends the response to the client. In the send thread I loop through the server's context list and look for the cont...
When i send()/write() a message over a tcp stream, how can i find out if those bytes were successfully delivered? The receiver acknowledges receiving the bytes via tcp, so the senders tcp stack should know. But when I send() some bytes, send() immediately returns, even if the packet could not (yet) be delivered, i tested that on linux ...
Below is a Perl script whose sole purpose is to receive an HTTP request, and spit out "503 Service Unavailable" and a short message. It works fine, except in many cases, the connection resets, which causes the browser to show an error message. This is on Win32. I have no idea what's wrong with it. #!/usr/local/bin/perl use strict; use ...
Does anyone know what is the maximum number of concurrent TCP/IP connections on Windows XP SP3? I am trying to load test a machine and would like to know what is the max number of tcp connections that can be opened by an application (in my case, java application) towards that machine. ...
Hi, I was wondering how tcp/ip communication is implemented in unix. When you do a send over the socket, does the tcp/level work (assembling packets, crc, etc) get executed in the same execution context as the calling code? Or, what seems more likely, a message is sent to some other daemon process responsible for tcp communication? Th...
What is the difference between ACTIVE and PASSIVE connect in RFC 1006 TCP connections? ...
The software I'm working on needs to be able to connect to many servers in a short period of time, using TCP/IP. The software runs under Win32. If a server does not respond, I want to be able to quickly continue with the next server in the list. Sometimes when a remote server does not respond, I get a connection timeout error after roug...
Situation: My ASP.net application connects to another system for information via a TCP Connection I am trying to simulate 100 people sitting & logging to my ASP.net application at the same time and connecting to the TCP Connection Will creating a windows Application with 100 threads trying to connect to the TCP Connection provide the c...
I'm not really familiar with the connection protocols. I'm using the following code to examine connect() so I can get the hostname: #ifndef NI_MAXHOST #define NI_MAXHOST 1025 #endif int error; char hostname[NI_MAXHOST] = ""; error = getnameinfo(serv_addr, addrlen, hostname, NI_MAXHOST, NULL, 0, 0); if (error !=0) { ALogTC...
My code basically needs to start up a simple chat server with a client. Where the server and the client can talk back and forth to each other. I've gotten everything to be implemented correctly, but I can't figure out how to shut down the server whenever I'm done. (I know it's ss.shutdown()). I'm wanting to end right now based on a...