About TCP Simultaneous Close

Hello everyone I am a for students from China, here is my problem, my English is not good, this is done by google translate.
Lab Topology
Environment
RHEL6.3 server + sock 0.3.2
Host 1.1.1.1 Entry sock -v  -b 12345  2.2.2.2 43415
Host 2.2.2.2 Entry sock -v  -b sock -v -y 3000 -b 43415  1.1.1.1 12345
//#: -y n  #ms for SO_SNDTIMEO (send timeout)
Theoretical Results That RFC Can Be Described Within The Framework of
Come From
RFC 793（Page 37）    and 《The TCP/IP Guide Version 3.0》（page 886 “Simultaneous Connection Termination”）
The truth of the matter was quite different .
Only Host 2.2.2.2 Reply ACK。Several attempts Failure。Does not appear, RFC 793 described phenomenon。
Doubt？
①
No.3 and No.4 Time Interval 0.04900300-0.01900100 = 0.030002======>TCP Simultaneous Open Result Full
No.19 and No.20 Time Interval 56.2792190-56.2762190 = 0.003======>TCP Simultaneous Connection Result Bad
I Do Not Know Where The Wrong？
②Guess！？
If Host 1.1.1.1 The first receive the ACK ，From CLOSING—>TIME-WAIT，Once go in TIME-WAIT Status ，TCP Stop Send Package（ACK）？
Hoping to be answered here
Sincerely Blessing
Regards

thanx for your replies i was very glad
AND i have one more question can you give me some examples about file transferr please? let's say sample codes like befere.
thank you.

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thanx for your replies i was very glad
AND i have one more question can you give me some examples about file transferr please? let's say sample codes like befere.
thank you.

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hi
i'd like to ask a question.
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http://www.codeproject.com/Articles/9538/Exception-Handling-Best-Practices-in-NET
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Should I upload my code??

my new version of code...
but there are still some problems
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Question about FMIR - open close fm periods

A simple question:
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A

Hi,
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JLB

Running XP,also asks to send error report about wanting to close mouse is freezing since new f/f4 installed on 2.4 laptop

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Questions about AE Simultaneous 802.11n

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Suggest to have more information about ducument line close status

Version: (Please provide the current version)
2005B Patch 35
Description of requirements: (Please provide a detailed description)
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     1-2 close by hand because customer modification
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     (3) Maybe after partial delivery, the price getting lower for left quantity or ship date modified for left quantity.
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Version: (Please provide the current version)
2005B Patch 35
Description of requirements: (Please provide a detailed description)
     We cant tell line status as close but which type in default report or query report
     Mainly there are 3 type :
     1-1 close by hand because typing mistake
     1-2 close by hand because customer modification
     1-3 close by target document normally
     1-4 close by target document normally but return
Business needs: (Please describe the impact on your business, if the functionality is not realized)
     For this reason, when boss ask for sales report from sales order, we can't tell the number
     and have some fake number and when the line is closed, we can't ask customer put more reason.
Valid as of: (Date that this legal requirement is applicable)
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Examples: (Please describe a typical example, how the functionality should work.)
     For Exemple - Sales Order Report or Query Report for Sales Order
     When the line status is close in Sales Order, there are a few situation.
     (1) Maybe after partial delivery, the customer cancle left quantity.
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         for a new line to modify.
     (3) Maybe after partial delivery, the price getting lower for left quantity or ship date modified for left quantity.
     (4) More there maybe some data wrong after partial delivery and need to return to redo again.
Current Workaround: (Please describe the workarounds you are using at the moment)
     Close whole document and put status reason with user define field on header.
     Rewrite sales report by query and use the user define as flag.
Proposed solution: (Please suggest how the new functionality should work)
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Ricardo,
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Put the looping animation inside a movie clip symbol. Movie
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TCP Open and Close using NI TCP VI's

Do I need to close the TCP connections on both ends. For example, I have a "server" that Listens and then a client that opens the TCP connection. Do I have to close the TCP connections on both ends. I'm closing it at the client side but is it also suppose to be closed at the Listening end?

Guy04 wrote:
Do I need to close the TCP connections on both ends. For example, I have a "server" that Listens and then a client that opens the TCP connection. Do I have to close the TCP connections on both ends. I'm closing it at the client side but is it also suppose to be closed at the Listening end?
Whenever you optain a LabVIEW refnum through an Open or similar function you should close it at some point too. A TCP refnum is really sort of a pointer to a local network socket and therefore represents resources in the form of memory and network stack management information. Not closing a connection refnum returned by the listen node may prevent your server to serve new connections after some time, since all internal network ports are blocked or the nework stack runs out of resources.
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Rolf Kalbermatter
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a division of Test & Measurement Solutions

TCP/IP problem: closes on client side, not on server side, can't reconnect!

Hey folks. I have a Java servlet that establishes a TCP/IP connection (via the Socket class) to a credit card processing company. Sometimes (usually early in the morning), for some reason the servlet starts timing out when using the socket (read timeouts), and the servlet responds by attempting to close() the socket, then re-open. The reopen doesn't work (no route to host).
The credit card processing company put a sniffer on their end, and they don't see anything when our reads time out or when we subsequently do a close(). Thus, they assume the connection is still established. When we try to open a new connection, our SYN packets do get through to them just fine, but they reply with RST packets because they think the prior connection is still established (thus they reject the new connection attempt)... but for us, that connection had gone dead.
They recommend we send FIN packets to them etc., i.e. that we do a proper TCP/IP close.... but if the connection suddenly goes dead to us, we can't do that... our close() attempts send absolutely nothing to them (no FIN packets, nothing at all).
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Please help if you can... right now, the connection can be down for hours because of this (with many fruitless incidents of our open-attempt SYN's responded to with RST's), and we have to call the credit card processing company to have them reset the port, which allows our next open attempt to work.
Thanks!

Strange... You say:
Thus, they assume the connection is still established. When we try to open a new connection, our SYN packets do get through to them just fine, but they reply with RST packets because they think the prior connection is still established (thus they reject the new connection attempt)... but for us, that connection had gone dead.
According to me, normal TCP behavior shouldn't behave like that.
A connection is identified by the two ends. Each end is a pair of <IP><Port>... This pair is likely to be the same all the time on the server, but will change on the client. The first time you issue a connection to the server, you will have a TCP connection identified by <ClientIp><FreeLocalPort1>-<ServerIp><ServerListeningPort>. The second time you connect, another free local port will be used. The previous cannot be reused - either because still in use, or because of a kind of 'grace' period during which this port number cannot be reused (this is to prevent mis-interpretation of packets that might be delayed on the network - connection is in the state TIME_WAIT).
Therefore, I don't understand why the server replies with RST when your client tries to reconnect.
Unless it has nothing todo with the TCP layer itself... You will see the same RST packet if the server application itself (not the TCP layer) refuses the connection because of some logic that says 'only one connection per client host'. If the server didn't notice your first connection was dead, it is likely to refuse your second attempt. See what I mean?
Remember a TCP connection can be half-closed. This means that if your client closes the connection, the server won't be able to send you anything but can still read what you send. In this case, if the server sits waiting for your data, it will never detect the connection lost... This is why most tcp daemons start a timer when reading incoming data. After a predefined period of inactivity, they decide the connection is dead and will close their side of the pipe - the connection is now fully closed.
Hope it was clear (despites my poor English and the very late hour in the night ;-)
Can point you to more accurate TCP doc if needed.
-Bertrand

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Anyone know what these TCP ports are used for?
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4510
4509
2222
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12EFC1C0 172.16.8.3.14401        10.8.2.14.49              TIMEWAIT
1CC4F57C 172.16.8.3.26963        10.8.2.14.49              TIMEWAIT
1A419F90 0.0.0.0.4510            *.*                       LISTEN
1C581740 0.0.0.0.4509            *.*                       LISTEN
1A417BBC 0.0.0.0.2222            *.*                       LISTEN
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12FB099C 10.8.10.2.2222          10.8.1.42.2233            CLOSEWAIT
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1CD47780 10.10.0.3.2222          10.8.1.15.3917            CLOSEWAIT
1CDDBCE0 10.8.10.2.2222          10.8.1.42.3964            CLOSEWAIT
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System image file is "disk0:c7600rsp72043-advipservicesk9-mz.122-33.SRD3.bin"
Tks
Frank

Frank
I can offer some suggestion about one of your port numbers. TCP port 49 is used for TACACS. If you are using TACACS for authentication, or authorization, or accounting then we know why port 49 is open and blocking TCP49 will prevent TACACS from working with your router.
I have no insights or suggestions about the other port numbers that you mention.
HTH
Rick

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Hi,
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Broker Startup Info:
================================================================================
Open Message Queue 4.3
Sun Microsystems, Inc.
Version: 4.3 (Build 7-g)
Compile: Fri Nov 7 19:11:27 PST 2008
Copyright (c) 2007 Sun Microsystems, Inc. All rights reserved. Use is
subject to license terms.
================================================================================
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        at com.sun.messaging.jmq.jmsserver.service.ServiceManager.stopAllActiveServices(ServiceManager.java:430)
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        at com.sun.messaging.jmq.jmsserver.BrokerStateHandler$ShutdownRunnable.run(BrokerStateHandler.java:383)
        at java.lang.Thread.run(Thread.java:619)
[30/Jan/2009:11:45:17 MST] Session: Resuming Session [5282756623254863360][0]Consumer.java: resuming after detatch Consumer - Q:temporary_destination:__queue_10.80.165.6_65423_1:[consumer:5282756623254870016, type=CLIENT_ACKNOWLEDGE]
[30/Jan/2009:11:45:17 MST] JMX Connector Server jmxrmi stopped successfully
[30/Jan/2009:11:45:17 MST] Cleaning up transactions on connection IMQConnCLOSED,[email protected]:65423,admin:44113
[30/Jan/2009:11:45:17 MST] Destroying temp destination Q:temporary_destination:__queue_10.80.165.6_65423_1 on connection death
[30/Jan/2009:11:45:17 MST] [B1159]: Destination temporary_destination://queue/10.80.165.6/65423/1 [Queue] has been destroyed
[30/Jan/2009:11:45:17 MST] WARNING [B2181]: Removing 1 messages associated with destination temporary_destination://queue/10.80.165.6/65423/1 [Queue]
[30/Jan/2009:11:45:17 MST] Cleaning up transactions on connection IMQConnCLOSED,[email protected]:65423,admin:44113
[30/Jan/2009:11:45:17 MST] [B1066]:   Closing: [email protected]:65423->admin:44113 because "[B0061]: Client exited without closing connections". Count: service=0 broker=0
[30/Jan/2009:11:45:17 MST] closed connection IMQConnDESTROYING,[email protected]:65423,admin:44113:
java.io.IOException: [B4117]: Unexpected Broker Exception: [destroyed Connection]
        at com.sun.messaging.jmq.jmsserver.service.imq.IMQIPConnection.writeData(IMQIPConnection.java:1563)
        at com.sun.messaging.jmq.jmsserver.service.imq.IMQIPConnection.process(IMQIPConnection.java:631)
        at com.sun.messaging.jmq.jmsserver.service.imq.OperationRunnable.process(OperationRunnable.java:170)
        at com.sun.messaging.jmq.jmsserver.util.pool.BasicRunnable.run(BasicRunnable.java:493)
        at java.lang.Thread.run(Thread.java:619)
[30/Jan/2009:11:45:18 MST] [B1048]: Shutdown of broker complete.
[30/Jan/2009:11:45:18 MST] Broker exiting with status=0 because [B1199]: Shutdown Requested by adminIf more detail are needed, please ask and I will supply whatever is necessary...
Thanks.
-Howard
Edited by: Turret on Jan 30, 2009 1:10 PM

Hi Tom,
Thanks for the quick response!
I am glad to hear that the log level is the reason for the output and not an issue with the broker!
Thanks again....
-Howard

Send multiple strings over TCP - Like messenger service

Hello all Java Coders,
I'm new with TCP programming.
I'm beggining to learn about TCP and sockets connections in Java. In order to achieve this, I was coding a mini-program so I can learn a little bit about this.
I'm trying to make a simple TCP program.
The server sends a string to a client...
I already searched for a couple of hours in google and so on, about what I'm doing wrong.
[The server code (Just click)|http://pastebin.com/m39fd1273]
[The client code (Just click)|http://pastebin.com/m57471803]
I hope that someone can help me with this and, if you have patience, please tell me the reasons my code doesn't work.
Many thanks,
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P.S.: I think that the problem is on the server side...

Sorry jverd.
I was just trying to put things organized.
Well, I can't get the String to be sent to the client.
No error occurs.
Server:
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        while(!data.equalsIgnoreCase("end")) {
            System.out.print("String to send: ");
            data = input.nextLine();
            System.out.print("Sending string: '" + data + "'\n");
            out.print(data);
        }Client:
        try {
            skt = new Socket("localhost", 1234);
            System.out.println("Connecting...");
            if (skt.isConnected()) {
                System.out.println("Connected!\nPreparing data exchange...");
                stream = skt.getInputStream();
                inputStream = new InputStreamReader(stream);
                in = new BufferedReader(inputStream);
                System.out.println("Done!\nReady to Receive!");
            } else {
                System.out.println("Server not available!\nExiting...");
                skt.close();
                System.exit(1);
        } catch (IOException ex) {
            System.out.println("Ups, didn't work!");
            System.exit(1);
        while (!data.equalsIgnoreCase("end")) {
            while(!in.ready()) {}
            data = in.readLine();
            System.out.println("Received String: '" + data + "'");
        }

Close Front Panel Causes System Hang.

I have an application where there are several front panels that I would like to have open at once, but where when they stop they would close. I was using the scripting function fp.close - but as the application has got more complicated this seems to work less and less well. Basically when i hit close, the system hangs for a few seconds, then the time critical stuff i have tends to timeout and then crash, and everything goes funny for a while.
My (uneducated) guess is that when it closes a front panel it drops loads of stuff straight out of memory - in an uncontrolled way.
After going for a cup of coffee it usually sorts itself out. But clearly this isn't a sustainable solution for my application or my kidneys.
Am I doing something wrong? - Is there something i should do to allow the Vi to finish before i try to close it? Should i be releasing references or somethign to make things better. I thought about running the close vi sub as a new thread - but not sure if this would actually do anything different.
Attached - the subroutine that i pass a vi ref to.
Attachments:
RunningVis_CloseSubVi.vi ‏17 KB

There's nothing in the attached VI that would necessarily cause your problem. I would, however, suggest that you feed your reference through the nodes in proper flow control method rather than branching off like you've done.
When a VI fails to close quickly, I have most often found it's due to open references which aren't explicitly closed. File references, VI references, multiple calls in a loop acquiring the same reference over and over without releasing it, .NET calls not being closed - that kind of thing.
Richard

About TCP Simultaneous Close

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