Re: [ns] 'Handoff Attempted' message
See following link, where it was already reported as a bug, because there is no point of doing a Handoff in a NON-INFRASTRUCTURAL environment. It includes a simple solution also. (Note: The asterisks (*) in the snippet of the code are extra, ignore them...) http://mailman.isi.edu/pipermail/ns-users/2008-December/064100.html Mayur Hi, I was wondering if anyone had any ideas what the message 'Client X: Handoff Attempted' means, which is occasionally produced when running simulations on ad hoc routing protocols (e.g. AODV, DSDV). I've looked around the list and on internet sites and found the question asked many times, but they never seem to have been answered. I'm assuming this message is just informative and that no error has occurred, but it would be nice to know what it is referring too. I've tried looking in the ns-2 source code to figure out where it is generated but haven't been able to find out so far. Any suggestions welcome. Cheers, Tim
Re: [ns] is there any one can tell me something about TCP tracefileanalysis without using some software
In the script (e.g. a Perl file) that analyzes the trace file with UDP, you need just change the word `udp' with `tcp'. I suppose this is what you want, OR your question is not understood well. Mayur Hello All, I have searched the internet for quite some time, however, I always find that the tracefile analysis is almost always target at UDP, not TCP. I want to know if any one can tell me how to analyze the TCP part (right now, I only searched out that many people can finish the thorough part of TCP) Thank you for your help. Sincerely.
Re: [ns] Set duration value
What do you mean by SPECIFIC duration value? It is calculated as per the 802.11 std and filled in the duration field of the header. See Mac-802_11.cc file for details. Mayur Hello everyone Can anyone tell me how can I set a specific duration value for request-to-send (RTS) and clear-to-send (CTS) frames in NS2? Thanks in advance
Re: [ns] What does the error Segmentation Fault means and how diserror can be rectified.......
`segmentation fault' is an error related to improper memory usage (e.g. accessing a location out side the allocated data segment for the process). It can best be analyzed by ddd (with gdb) and valgrind kind of tools. Mayur H ns-usersIf any of you guys know what does the error segmentation fault means and how this error can be solved, please send me the solution and links if you have any regarding thisI am trying to simulate a scenario for a 650 seconds...After simulating for 16 seconds , I have a error saying Segmentation Fault. I am getting a trace file but only for that 16 seconds.please help me regarding this so that i can get the trace file completely for my simulation time of 650 seconds.Any help is greatly appreciated. Thanks in advance.
Re: [ns] carrier sense
NAV is not a table. For a particular node its NAV is a simple variable used to store a number which is the duration (in microseconds) for which it freezes its backoff downcounting, it it is ON. You can know this value by accessing the nav_ (a double type of variable of Mac802_11 class in mac/mac-802_11.h). Hope this helps Mayur hi all it's true the node uses the carrier sense before sending the data. as per my understanding the NAV for the nodes in the carrier sense rage is updated. Nodes uses this nav to determine the time after which the it is permited to send the data. my promblem is to use the entries in nav for my work.how can i access the nav table. Neeraj Gupta Assistant Professor HOD, CSE IT Department Hindu College of Engineering Sonepat
Re: [ns] How to reduce execution time of scenario generation (using setdest)
Thanks a lot Sriram!. It really cut the execution time drastically from 2.8 minutes to 0 (negligibly small number of) seconds. Actually, I earlier avoided the God related statements, but it did not help more. After I commented floyd_warshall and neighbour related functions, it has reduced drastically. regards, Mayur this is sriram from iit kgp again in scenario gen ie setdest.cc you can delete unwanted portions which u may not use and this shuld reduce scenario generation time. like for my application i did not require functions like flloyd-warshall and the neighbour functions , god functions etc. remove them and ur scenario file generation shuld be faster. in the scenario file u basically require only lines for initial postion and setdest (set destination) neighbour reachable etc are discovered by the routing protocol themselves -- B Sriram India mob : 09733706981 Dear Mayur, Setdest has many nested for loops in which it is computing neighborhood of nodes, You remove all those nested loops as well. The actual code for generating random movement is not more that 50 lines. All other code is of god only. Previously when I worked with it, I did this optimization and it scalled well even for 1000 nodes(it generated the mobility scenario in less than 1 minute) I think this helps. regards, Manish On Sat, Feb 28, 2009 at 2:25 PM, Mayur Mansukhlal Vegad ma...@ee.iitd.ac.in wrote: I had already tried it by commenting the show_diffs() method call statement. But it didnot help. The only four statements printing God related stuff are those containing GOD_FORMAT and GOD_FORMAT2, which are inside the show_diffs() function. I commented that calling stmt. And the scenario file had no GOD stmts then. But still it takes similar amount of time. BTW thanks for your considerations! Mayur If you look at the code, setdest is spending most of the time in generating god entries. so if you are not interested in them, you can comment out the code which calculates and generates god entries which will reduce the execution time significantly. regards, Manish On Sat, Feb 28, 2009 at 1:06 AM, Mayur Mansukhlal Vegad ma...@ee.iitd.ac.in wrote: Dear all, scenario generation takes around 2.5 to 3 minutes for large number (eg 100) of nodes. It is too much. After that the ns simulation takes another minute or more. Could anybody guide how to reduce the execution time particularly of the setdest tool? with regards, Mayur
[ns] How to reduce execution time of scenario generation (using setdest)
Dear all, scenario generation takes around 2.5 to 3 minutes for large number (eg 100) of nodes. It is too much. After that the ns simulation takes another minute or more. Could anybody guide how to reduce the execution time particularly of the setdest tool? with regards, Mayur
Re: [ns] Fw: trace file
Better you refer Ch. 16 of ns-manual for good understanding. Eng Rony hi all i run simple-wireless.tcl example from Marc Greis' tutorial section IX. Running Wireless Simulations in ns and i want to know what each field in o/p trace file means, for example: s 0.029290548 _1_ RTR --- message 32 [0 0] --- [1:255 -1:255 32 0] M 10.0 (5.00, 2.00, 0.00), (20.00, 18.00), 1.00 s 10.0 _0_ AGT --- 2 tcp 40 [0 0] --- [0:0 1:0 32 0] [0 0] 0 r 10.0 _0_ RTR --- 2 tcp 40 [0 0] --- [0:0 1:0 32 0] [0 0] 0 ..D 76.430622539 _0_ IFQ ARP 2 tcp 80 [0 800] --- [0:0 1:0 32 1] [0 0] 0 D 76.430622539 _0_ RTR CBK 8 tcp 80 [0 800] --- [0:0 1:0 32 1] [0 0] 0 s 100.337960577 _1_ RTR --- 80 ack 60 [0 0] --- [1:0 0:0 32 0] [28 0] 0 r 100.340096680 _0_ AGT --- 72 ack 60 [13a 1 800] --- [1:0 0:0 32 0] [24 0] 1 0 r 69.501265756 _1_ RTR --- 15 message 32 [0 800] --- [0:255 -1:255 32 0] i want to know also what means by agentTrace,RouterTrace,MacTrace thanks
Re: [ns] several sinks on single node
Dear Abdelhak, Answers are intermingled with your questions... Abdelhak Farsi wrote: Hi there, I assume that in 802.11 WLAN working in infrastructure mode, Your assumption is right but only for the latest version, 2.33. There are various versions of WLAN implementations available. Go through Section 16.3 in the NS (latest) Manual for further info. I have a base station sending different TCP streams to a single wireless station ( each stream is distinguished by the size of the packets sent and each stream represent a single application), my question is : Is it possible to define several sinks on the receiving wireless station to intercept all the streams? Yes, it is possible. A single node can have two (or more) TCPSink agents each receiving from different TCP source agents. What problem you faced, that could not be understood. best regards Mayur
Re: [ns] remove ns2
Dear Kamal, You need not remove it from your computer unless the Secondary memory is scarce, which I suppose, is not the issue. Just change the PATH, LD_LIBRARY and TCL_LIBRARY environment variables as asked after the installation of ns2.26, so that the ns2.26/ns is run instead of ns2.33/ns. And still you can switch to ns2.33 whenever you want just by following similar steps. To be more clever you can place some 'if . fi' statements in your HOME/.bashrc script so that you can switch to any of the available versions of ns. with regards, Mayur eng Rony wrote: Eng Rony how can i remove ns2.33 and i want the full steps to install ns2.26 thanks
