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

Epidemic routing - bundle size issue
by Sandra Siby 17 Mar '14

17 Mar '14

Hi, We have the following test scenario: 2 fixed nodes (a sender and a receiver) A and D and 2 mobile nodes, B and C, moving between them. B and C start from A and D respectively and move towards each other. They are in contact for a short duration in between A and D. When they are in contact, they do not have any contact with the fixed nodes. We send data from A and use the mobile nodes to carry the bundles to D. The configuration we were using is epidemic routing and we send a file of 12MB, fragmented proactively in 1MB payload size. At the sender, we get 12 bundles of 976.7K and 1 bundle of 569.3K. We assumed that the same number of bundles with identical sizes will be at the receiver. However, after all the bundles have been delivered at the receiver, we see that there are 11 bundles of 976.7K, 1 bundle of 12.1K and one bundle of 540.1K. Is it normal for there to be a discrepancy in the bundle sizes on both sides? If so, why is there a difference? Note that we do not run the dtninbox application on the receiver side to extract the file to the application layer. It would be great if you could also give us a short description of how epidemic routing is implemented in your code. Regards, Sandra

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Bundle Order
by Theodoros Bourchas 12 Mar '14

12 Mar '14

Hi, My experimental scenario is the following one: I have a sender and a receiver node that are not in contact with each other and a mobile node (intermediate) that takes bundles from the sender in a contact interval of some minutes and delivers them to the receiver in another contact interval. I use proactive fragmentation. I have a big file of 200MB and I fragmented to bundles of 100KB. So, on the sender side (temporary bundle directory) I have 2098 bundles (of 97.7KB approximately). I want to know in what order bundles are created and sent in the temporary folder on the sender/intermediate/receiver side. For example, if one bundle is not received completely, does it remain in the temporary folder of the intermediate node? And if this is the case, it remains on top of the transmission queue (so it would be the first bundle sent in the next contact) New bundles that are received and stored in the temporary directory of the intermediate node would be first in the queue? Thanks, Theodoros

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Recording info about transmissions between nodes
by Luís Carlos Guedes 12 Mar '14

12 Mar '14

Hello, Our goal is to use IBR-DTN in a small testbed (50nodes), where we will do measurements and calculate statistics about the moments when the bundles are sent, received, and transfered from node to node (including information such as the source node, destination node, amount of data transfered), for example, this situation from NodeA to NodeB, passing throw NodeC: Emitter: "BundleX SENT from NodeA to NodeB" Receiver: "BundleX_Received from NodeA - completed (10MB)" (or, in case of 3 nodes): in nodeC: "transferofbundle (10MB) from NodeA to NodeB - completed" We want to store this information in a file as small as possible, so we need to find the logging instructions for these events in the code, so as to also log to our own file each time one of these events happens (and thus avoid recording and storing all the other log messages). We have studied the code, but it is hard to find these things clearly, as the logging seems to use several different routines and sub-routines. If you could point us to the most important code files that we should look into and change so as to log these informations into our own log file, that would be very helpful. Thank you, Luís Guedes

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Multicast discovery_address
by Maël Auzias 10 Mar '14

10 Mar '14

Hi, When the discovery_address is set to either 192.168.0.255 (nodes are on the network 192.168.0.0/24), or 255.255.255.255 an error message appear: IPNDAgent : join failed on wlan0; 22 : setsockopt() Can't the discovery_address be set to something else than 224.0.0.x ? Thanks for further replies! Have a nice day.

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Multi EID per node
by Maël Auzias 10 Mar '14

10 Mar '14

Hi (again), I wish my nodes to have more than one local EID. How can it be set ? In the conf file if there are 2+ local_uri just the last one is used. I use then a group where there is only one node. Something like dtnrecv --group dtn://singleton/node01/sensor, but is there any other way to make it *cleaner* ? Note: I have the same issue with DTN2. Thanks for further replies! Have a nice day.

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Discovery version 0 issue
by Maël Auzias 10 Mar '14

10 Mar '14

Hi (again again), When the IBR-DTN nodes are set to use the discovery_version =0, which is DTN2 compatible, the IBR-DTN nodes do not discovery each others. When a bundle from an IBR-DTN is sent to another IBR-DTN node the bundle goes through a DTN2 node (flooding routing) to reach the destination even though they are in the Wi-Fi range. Is that a known issue ? Did someone got the same ? How to manage it ? Thanks for further replies! Have a nice day.

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log files information
by Luís Carlos Guedes 10 Mar '14

10 Mar '14

Hello, I would like to know where (in which files) you make the logs files because i wanted to collect some extra information each time a bundle is sent/ transfered/ delivered. Thank you in advance,Luís Guedes

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Nodes discover each other, but do not communicate ?
by Maël Auzias 07 Mar '14

07 Mar '14

Hi you all, *== this is not a question, but an answer ==* I went through an issue, in order to help others who might had the same problem I'm writing down the problem description and the solution. Actually I found the solution while writing the "question" e-mail. *TL;DR:* Ibr-dtn nodes discover each other but do not ping, neither send to another ? Make you sure you stopped the service:* #service ibrdtnd stop* When you dtnsend, if the service is running, in the same time that your dtnd -i <nic>, the dtnsend use the service and then, maybe, the wrong interface and the wrong configuration file -as far as I understand-. Make sure you're using your own conf file with dtnd command (and the option -c <path to conf file>) and the right interface by shutting down the service. Environment: - #dtnd -i wlan0 -v - PC can ssh each other - ibr-dtn had been installed from package I do not know if it worth adding this in the FAQ<http://trac.ibr.cs.tu-bs.de/project-cm-2012-ibrdtn/wiki/FAQ>, that's up to you to choose. Have a nice day!

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IBR-DTN performance with big files and small bundle-fragments
by Theodoros Bourchas 06 Mar '14

06 Mar '14

Hi, I want to transfer 500MB, using proactive fragmentation of 100K bundle_size. I have changed the parameters in the configuration file of the sender as below: option limit_payload 100K option fragmentation yes option limit_lifetime 60000 option bundles_in_transit 1000 So, with above options, I would expect around 5000 bundles of 100K stored in the temporary folder of my device. Observing the logs, I could see in the daemon of the sender 4207 'TransferCompletedEvent' and 4212 'BundleReceivedEvent' in the daemon of the receiver. After some time that the experiment was running smoothly, 'TransferAbortedEvent' were triggered at the sender and 'BundleExpiredEvent's were triggered in the receiver. As a result, the already stored bundles in the receiver side started to being deleted. Any guess of why there is such a behavior? The option 'limit_lifetime' is expressed in secs, correct? Can you explain what is defined with option bundles_in_transit? Thanks, Theodoros

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Set up static routes in OpenWRT
by Theodoros Bourchas 03 Mar '14

03 Mar '14

Hi, I want to set static connections from dtn://host2 to dtn://host4 and dtn://host5 in parallel and send file to dtn://host6 which is unreachable by all. What should I configure at the configuration file in OpenWRT? I have made the following but packets did not arrive to 4 and 5 respectively. config 'daemon' 'main' # values: none | default | epidemic | flooding | prophet option routing default # static routing rules # - a rule is a regex pattern # - format is <target-scheme> <routing-node> # config 'static-route' # list pattern .... # option destination .... config 'static-connection' option uri dtn://host4 option address 10.0.1.4 option port 4556 option protocol tcp option immediately yes config 'static-connection' option uri dtn://host5 option address 10.0.1.5 option port 4556 option protocol tcp option immediately yes I missed sth for sure, but what? Best, Theodoros

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