June 2014 - Ibr-dtn - lists.ibr.cs.tu-bs.de

ibr dtn (from Indonesia)
by abu fahruddin 27 Nov '14

27 Nov '14

Dear Sir, I am herman yuliandoko, currently i am lecture at State Polytechnic of Banyuwangi. And now I am doing research in DTN. I try to install DTN from wget -O - http://download.opensuse.org/repositories/home:/j_morgenroth/xUbuntu_12.04/… sudo apt-key add - https://trac.ibr.cs.tu-bs.de/project-cm-2012-ibrdtn/wiki/ibr-dtn-tut but i get problem to acces above repository W: Failed to fetch http://download.opensuse.org/repositories/home:/j_morgenroth/xUbuntu_12.04/… 404 Not Found I am using ubuntu for my trial, could you help me to solve above problem. Your advice is wellcome. best regards herman yuliandoko +6281334436478

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Android Application
by Ghada Jaber 13 Nov '14

13 Nov '14

I've imported the android application ( ibr-dtn) but when i run it , it tells me ibr-dtn has stopped . Could any body help me ? because i dcouldn't figure out why ? Thank you Ghada Jaber Etudiante en 5eme année Réseau informatique et Telecommunication a l'INSAT Stagiaire a l'IRIT/ENSEEIHT Tel : 003385681703 email : jaberghada(a)yahoo.fr Skype : ghada.jaber90

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ibrdtn and java
by Maël Auzias 30 Jun '14

30 Jun '14

Hi everyone ! I'm working on the java part of the ibrdtn <https://github.com/ibrdtn/ibrdtn/tree/master/java>. Nice clean code which works fine. Nonetheless I have some difficulties to use received bundles. Indeed I cannot find a way to know to which EID a bundle had been sent neither how to use its payload outside of the thread <https://github.com/ibrdtn/ibrdtn/blob/master/java/example/src/ibrdtn/exampl…> printing in the LOG the bundle. Also... I wonder if I didn't miss the documentation of this part, I just can't find it! Have a nice day ! Best regards, --- Auzias Maël - http://auzias.net PhD candidate <http://auzias.net/?p=phd> - IRISA Member of the Scientific Council <http://auzias.net/Generation14/index-en.html> GSM : *0033 695 118 774*

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Time synchronization
by Luís Carlos Guedes 25 Jun '14

25 Jun '14

Hello, I would like to know if there is a way to know the date/time of the application in IBRDTN (not the local date). I want to know the time it takes to send a file from one (wireless) node to a server on the Internet. The problem is that if the boards are not synchronized, so I get results that are probably not correspondent to reality. I defined two nodes connected to the Internet as masters and the other as slaves, the problem is that I am working with different devices on multiple networks, all in a testbed, they are not all in direct contact with each other (or in direct contact with the master nodes) but there is an end-to-end path. So, I should be able to ping with dtnping end-to-end but it does not work. In between some nodes the dtnping works but in between some others it does not (I need to add the option --lifetime, but when this happens the results are not correspondent with reality). If you know some way to help me I would appreciate. Thank you. Best regards, Luís Guedes

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Re: [ibr-dtn] threads
by Sebastian Schildt 25 Jun '14

25 Jun '14

Ok, but it still seems like it could be a bug. CPU-wise you should be pretty save, it seems it is the CPU as in the old Ubiqiti RouterStation Pro, and we have several of those running with IBR-DTN. Below you said, you saw nearly " 3K of bundles per minute“ every minute. Did this change with epidemic, or is the CPU usage just lower? Are those bundles from your application, that get replicated over and over, or are this routing handshakes (they are sent from endpoint <EID>/routing, so they can be spotted in the log easily, i.e. if the dameon is started with -v or) _Normally_ I think static connections should not interfere with Prophet. However, what exaclty do you mean with static connections: 1. An always on connection with another DTN node (i.e. ethernet cable) -> That works fine 2. A static neighbor you declared in the configuration? That should also work. Maybe some useless routing handshake packets are generated if the neighbor s configured but not available, but since they have a short lifetime, that should not matter… 3. A static route in the configuration file? If so, what ist the route exactly? The weird thing here really is, that you expereince lower CPU load with Epidemic than with Prophet. That is suspicious, because Prophet does not do so much more. The more heavey parts such as creating and exchanging BloomFilters are in Epidemic as well… Next week our IBR-DTN archmage Johannes will be back on board. Maybe he has some additional ideas. While bundles might remain in storage until they are expired, this is similar in the worst case for Prophet to (i.e. if there is no path). I do not know, whether that is a problem with your storage, however, even Epidemic makes sure, that a bundle will only be transferred once to one peer, so at least bandwidth-wise it is not so much worse* Sorry, that most of this is guesswork. I am a bit out of ideas atm. But please post whatever details/findings you can come up with. Sebastian * However, retransmits might occur, if a node delivered a bundle directly, deletes it from its storage and afterwards looses his Bloomfilter state, because it is powered down. When it comes up again, it could get the bundles again, if others still have them in storage On 25 Jun 2014, at 18:45, Tiago Condeixa <tscondeixa(a)ua.pt> wrote: > Hi again Sebastian, > > I changed the routing protocol from prophet to epidemic and the CPU usage and load average decreased a lot, so It seems there is a problem with prophet or at least when It is mixed with static connections. > My main problem right now it that there isn’t ack in epidemic, and the bundles remain in the defined folder until the lifetime defined, even when they are delivered to the destination. > > thanks, > Tiago > > Begin forwarded message: > >> From: Tiago Condeixa <tscondeixa(a)ua.pt> >> Subject: Re: [ibr-dtn] threads >> Date: 25 Jun 2014 15:03:33 GMT+1 >> To: Sebastian Schildt <schildt(a)ibr.cs.tu-bs.de> >> >> Hi Sebastian, >> >> I’m using the new ibrdtn version 0.12.1 in all boards. You can find the board specifications in (http://routerboard.com/RB411UAHR), with CPU AR7161-BC1A. The bundles are stored in flash with default storage. >> The configuration file has the following configurations, the ones not shown are commented. This configurations are for the moving boards, while in the gateways I also have another interface with ibrdtn (wired) and a static connection to my server also running dtnd. >> fragmentation = no >> storage_path = /root/DTN/ibrdtn/bundles >> limit_storage = 3M >> discovery_address = 224.0.0.142 >> discovery_timeout = 5 >> discovery_crosslayer = yes >> net_interfaces = lan0 >> net_lan0_type = tcp >> net_lan0_interface = wlan1 >> net_lan0_port = 4556 >> routing = prophet >> routing_forwarding = yes >> routing_prefer_direct = yes >> dht_enabled = no >> >> I measured the gateway load average during almost a day, please see the attached pdf file. The three moving boards (now stopped in lab ensuring connectivity) and the gateway generate nearly 3K of bundles per minute, and all this data goes through the gateway until the server. The values seems quite high just for 4 boards with few bundles, so I assumed that in a dynamic scenarios with 50 or 100 boards and more information being collected I will have much more CPU usage and load average. >> >> I already know the neighbors and their IP addresses at the kernel level, so do you if I disable neighbor advertisements and routing and feed it directly from my kernel information I can reduce a lot the CPU usage, load average and memory? Do you think this high values are due to the tcp sessions transferring the bundles or they can also be generated by the control messages/processes? Do you have any more hits on how can I reduce the overall resources consumption of ibrdtn? >> >> I will continue measuring the load average changing some things in ibrdtn configuration. >> >> Thanks, >> Tiago >> > <uptime_737.pdf> >> >> >> On 25 Jun 2014, at 09:11, Sebastian Schildt <schildt(a)ibr.cs.tu-bs.de> wrote: >> >>> Hello, >>> >>> this is hard to diagnose… Generally speaking: If the DTN dameon is idling in the background and has no contact to neighbors, CPU usage schould be neglibile. If it connects and has a lot of bundles to transmit you might see it spiking. Can you describe more clearly, for how long CPU usage spikes are, and what happens in the network during that time? >>> >>> Your configuration regarding storage, and if you use it, security might help shed some light onto this. For example, one known reason for high CPU usgae could also be a corrupted SQLite storage. Another reasons might be a very, very slow storage (then you should see lots of IOWait in top). To check whether this is the reason, you could also start the deamon without any storage option set (it will work in RAM then). >>> >>> As a short-time fix, it should be no problem to set the niceness of IBR-DTN to 19 (man renice). This will not reduce load, but it will make sure that IBR-DTN does not take so much ressources from other processes away. However, in any case, in the low-traffic situation you lined out, IBR-DTN should not take that much ressources. Short spikes with high/full CPU load on contact can be expected, but they should not be that long that they increase your load average. >>> >>> Lastly, can you tell, what kind of processor you use? Is it a MIPS4k (like the good old TI AR7 found in old routers) or 24K (like the Atheros AR7xx family) variant? Maybe I can find something similar in our stack of hardware to get a better feeling what to expect :) >>> >>> >>> MfG >>> >>> Sebastian >>> >>> On 23 Jun 2014, at 15:40, Tiago Condeixa <tscondeixa(a)ua.pt> wrote: >>> >>>> Hi Sebastian, >>>> >>>> I have several moving single boards with IBRDTN collection and sending information each minute to a server through a few gateways. The dtnd deamon several times goes above 70% of CPU, which increases the load average (top or uptime) for values much higher than 1. It seems that sending packets increases a lot the CPU usage when compared with dtnd deamon running without any tool. Do you have any hit why this is happening? We cannot continue using the ibrdtn software with this really high values. >>>> >>>> Thanks, >>>> Tiago >>>> >>>> On 19 Jun 2014, at 10:13, Sebastian Schildt <schildt(a)ibr.cs.tu-bs.de> wrote: >>>> >>>>> As far as I know,we have never checked reducing the Thread stack size. However, considering that the RSS size is always significantly smaller than virtual memory, it seems, it could work. It is hard to influence the number of threads, because for every connection a couple of threads (3?) are spun up. So, the more neighbors you are connected to, the more threads you get. Basically the multi-threaded model is in the DNA of IBR-DTN because only these architecture will allow making use of multicore architectures. . However, according to our experience there is not much overhead from those threads. We have seen MUCH more threads than 25 on OpenWRT based MIPS boards without any problems. >>>>> >>>>> Also, if you remove a neighbor, after some while the number of threads should go down again (there should not be any "thread-leakage", if there is, it is a bug) >>>>> >>>>> Here are some more information regarding the maximum number of threads and influence on virtual memory: >>>>> >>>>> http://stackoverflow.com/questions/344203/maximum-number-of-threads-per-pro… >>>>> >>>>> >>>>> But anyway, if you hit any walls, let us know :) >>>>> >>>>> Sebastian >>>>> >>>>> >>>>> Am 19.06.2014 um 10:55 schrieb Tiago Condeixa <tscondeixa(a)ua.pt>: >>>>> >>>>>> Hi, >>>>>> >>>>>> I install ibrdtn software in single board computers running OpenWrt with MIPS architecture and just 128M of RAM Memory. Because of this, I reduce the thread stack size in Thread.cpp file from 2M to 256K and virtual memory reduces a lot, and at least during the last day it didn’t crash. Do you tested the ibrdtn with smaller value or do you know if I will have a segmentation fault for larger scenarios? What is the operation requiring more memory by dtnd? I defined a path for the bundle storage. >>>>>> >>>>>> I also check dtnd process and it uses around 25 threads, which is a lot for our embedded system with other programs running. There is any change to reduce the number of threads? and how can I do it? >>>>>> >>>>>> thanks a lot, >>>>>> Tiago >>>>>> -- >>>>>> !! This message is brought to you via the `ibr-dtn' mailing list. >>>>>> !! Please do not reply to this message to unsubscribe. To unsubscribe or adjust >>>>>> !! your settings, send a mail message to <ibr-dtn-request(a)ibr.cs.tu-bs.de> >>>>>> !! or look at https://mail.ibr.cs.tu-bs.de/listinfo/ibr-dtn. >>>>> >>>> >>> >> >

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Re: [ibr-dtn] threads
by Tiago Condeixa 25 Jun '14

25 Jun '14

Hi Sebastian, I have several moving single boards with IBRDTN collection and sending information each minute to a server through a few gateways. The dtnd deamon several times goes above 70% of CPU, which increases the load average (top or uptime) for values much higher than 1. It seems that sending packets increases a lot the CPU usage when compared with dtnd deamon running without any tool. Do you have any hit why this is happening? We cannot continue using the ibrdtn software with this really high values. Thanks, Tiago On 19 Jun 2014, at 10:13, Sebastian Schildt <schildt(a)ibr.cs.tu-bs.de> wrote: > As far as I know,we have never checked reducing the Thread stack size. However, considering that the RSS size is always significantly smaller than virtual memory, it seems, it could work. It is hard to influence the number of threads, because for every connection a couple of threads (3?) are spun up. So, the more neighbors you are connected to, the more threads you get. Basically the multi-threaded model is in the DNA of IBR-DTN because only these architecture will allow making use of multicore architectures. . However, according to our experience there is not much overhead from those threads. We have seen MUCH more threads than 25 on OpenWRT based MIPS boards without any problems. > > Also, if you remove a neighbor, after some while the number of threads should go down again (there should not be any "thread-leakage", if there is, it is a bug) > > Here are some more information regarding the maximum number of threads and influence on virtual memory: > > http://stackoverflow.com/questions/344203/maximum-number-of-threads-per-pro… > > > But anyway, if you hit any walls, let us know :) > > Sebastian > > > Am 19.06.2014 um 10:55 schrieb Tiago Condeixa <tscondeixa(a)ua.pt>: > >> Hi, >> >> I install ibrdtn software in single board computers running OpenWrt with MIPS architecture and just 128M of RAM Memory. Because of this, I reduce the thread stack size in Thread.cpp file from 2M to 256K and virtual memory reduces a lot, and at least during the last day it didn’t crash. Do you tested the ibrdtn with smaller value or do you know if I will have a segmentation fault for larger scenarios? What is the operation requiring more memory by dtnd? I defined a path for the bundle storage. >> >> I also check dtnd process and it uses around 25 threads, which is a lot for our embedded system with other programs running. There is any change to reduce the number of threads? and how can I do it? >> >> thanks a lot, >> Tiago >> -- >> !! This message is brought to you via the `ibr-dtn' mailing list. >> !! Please do not reply to this message to unsubscribe. To unsubscribe or adjust >> !! your settings, send a mail message to <ibr-dtn-request(a)ibr.cs.tu-bs.de> >> !! or look at https://mail.ibr.cs.tu-bs.de/listinfo/ibr-dtn. >

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dynamic routing using prophet
by magda lena 20 Jun '14

20 Jun '14

Hi, I already try to use prophet between indirectly connected node trough node between both indirectly connected node and it work. now i want to analys about my implementation of this routing protokol (prophet), but i don't know what aspect of it that i can analys. i read about several parameter in prophet, like age_period and etc, but i still don't get it. can you help me, what parameter can i analys this routing protokol? thanks. > > you can use `iptables` to block traffic from nodeA to nodeC. If set > correctly before the startup of dtnd, the nodes won't discover each > other. > > Can't tell you the correct syntax right now, but there are lots of > tutorials online... >

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threads
by Tiago Condeixa 19 Jun '14

19 Jun '14

Hi, I install ibrdtn software in single board computers running OpenWrt with MIPS architecture and just 128M of RAM Memory. Because of this, I reduce the thread stack size in Thread.cpp file from 2M to 256K and virtual memory reduces a lot, and at least during the last day it didn’t crash. Do you tested the ibrdtn with smaller value or do you know if I will have a segmentation fault for larger scenarios? What is the operation requiring more memory by dtnd? I defined a path for the bundle storage. I also check dtnd process and it uses around 25 threads, which is a lot for our embedded system with other programs running. There is any change to reduce the number of threads? and how can I do it? thanks a lot, Tiago

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dynamic routing using prophet
by magda lena 18 Jun '14

18 Jun '14

hello, i have nodeA, nodeB, nodeC. all nodes are in the same range (directly connected) i want to route from nodeA to nodeC via nodeB but using prophet. can i set this manually, in order to make route from nodeA to nodeC via nodeB ? (nodeA and nodeC in the same range) thanks.

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dynamic routing using prophet routing protocol
by magda lena 16 Jun '14

16 Jun '14

Hello, i set routing=prophet in nodeA,B,C and i try to dtnping from nodeA to nodeC (nodeA and nodeC is not directly connected) when the dtnping still on going, i move nodeB from near nodeA and then come near node C and vice versa. but the dtnping ping in nodeA still got time out? is there any option to know that the bundle from nodeA to nodeC going trough nodeB ? Just set "routing = prophet" on all nodes. > > >

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