July 2013 - Ibr-dtn - lists.ibr.cs.tu-bs.de

transfer of bundles
by Bruno Tavares 15 Aug '13

15 Aug '13

Hello In order to analyze the results of some experiences I made, I need to know if two bundles are sent at the same time in one node. Let's say that the scenario has three nodes. The middle node receives a fragment from the first and starts to send it for the last node. In the meanwhile the first node sends a second fragment to the middle one while he is still sending the first one to the last node. What happen? Are the two fragments sent at the same time or the last fragment is only sent to the last node when the transfer of first fragment to the last node is finished ? Thank you Best regards Bruno Tavares

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Install problem on OpenWrt
by Christian Raffelsberger 25 Jul '13

25 Jul '13

Hello, I tried to install IBR-DTN on OpenWrt with the usual procedure: "opkg update" and "opkg install ibrcommon ibrdtn ibrdtnd ibrdtn-tools". However, I get an error message that the package "ibrdtnd" is unknown and there is indeed no package file for ibrdtnd at the build server. Has the install procedure changed recently or is there a problem with the OpenWrt build? The opkg sources entry looks like this: src/gz ibrdtn http://jenkins.ibr.cs.tu-bs.de/download/openwrt/repository/attitude_adjustm… Best regards, Christian

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size of bundle
by Bruno Tavares 23 Jul '13

23 Jul '13

Good morning. Is it possible to know the size of a bundle when it is received by the peer? I would like to have this information on the log but in the BundleReceivedEvent.cpp I cannot have access to this information. Thank you Best regards, Bruno Tavares

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IBR-DTN release 0.10.0
by Johannes Morgenroth 22 Jul '13

22 Jul '13

New Release 0.10.0 available! More than one year of development and testing have born a new release of IBR-DTN. With more stability, more features, complete fragmentation and IPv6 support this release has been natively ported to the Android platform. For a full list of features and changes watch the official changelog: http://www.ibr.cs.tu-bs.de/trac/ibr-dtn/wiki/changelog The packages for Debian, Raspbian and OpenWrt are currently in our build queue and should be available very soon. Kind regards, Johannes Morgenroth

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Re: [ibr-dtn] smallest openwrt router that can run ibr-dtn?
by Johannes Morgenroth 19 Jul '13

19 Jul '13

How do you define "small"? Physically small or small with resources? One earlier platform was the imote2 sensor node which is physically very small. Depending on the configuration the daemon should run on all devices with more than 16 MB ram. Currently we still targeting the ubiquiti router station for openwrt and do not have continuously tested any other device out there. Tom Sparks <tom_a_sparks(a)yahoo.com.au> schrieb: >I am wondering what is the smallest openwrt router that can run ibr-dtn? > > >--- >tom_a_sparks "It's a nerdy thing I like to do" >Child of the Internet born 1983 >PGP ID: A7EF6006 >Please use ISO approved file formats excluding Office Open XML - http://www.gnu.org/philosophy/no-word-attachments.html >Ubuntu wiki page https://wiki.ubuntu.com/tomsparks > >-- >!! 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://www.ibr.cs.tu-bs.de/mailman/listinfo/ibr-dtn.

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Android implementation doubts
by Guilherme Rolim 17 Jul '13

17 Jul '13

Hello, I'm coding a application for android based on the DTN Ping example, however, I don't quite understand the use of some classes. For instance, I am trying to get the neighbour list from the DTN app and send a bundle to each neighbour but I don't know how to get their addresses (something like dtn://example). I've managed to get the neighbour list using the getDtnService() getNeighbors() methods from the client, but there was no method to get their addresses. Could someone explain me the best way to do it? Also, is there any document that may help me understand the dtn api classes? Thanks in advance, Guilherme rolim

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Re: [ibr-dtn] Ibr-dtn Digest, Vol 36, Issue 2
by Bruno Tavares 16 Jul '13

16 Jul '13

Thank you for your answers realting this and the other subjects. I did change the timeout on the several lines of code having the instance of new TCPConnection(...,5). In most of cases the time when the transmission is stopped is right but sometimes it appears more 10 seconds than what it should. For example if the connection is stoped (5 seconds of connectivity) sometimes the line of code "Sender terminated by exception : output stream went bad ...." appears 10 seconds after than what it should. I already have in mind the 10 seconds of 2*5 seconds but sometimes it has more 10 seconds on the timestamp in this line of code and sometimes it dont (when it is right). Where can I see in the code the exact moment that the interface goes down to know exactly when the two nodes stopped the transmission of data? Best regards, BRuno Tavares ________________________________________ De: ibr-dtn-bounces(a)ibr.cs.tu-bs.de [ibr-dtn-bounces(a)ibr.cs.tu-bs.de] em nome de ibr-dtn-request(a)ibr.cs.tu-bs.de [ibr-dtn-request(a)ibr.cs.tu-bs.de] Enviado: terça-feira, 2 de Julho de 2013 11:00 Para: ibr-dtn(a)ibr.cs.tu-bs.de Assunto: Ibr-dtn Digest, Vol 36, Issue 2 Send Ibr-dtn mailing list submissions to ibr-dtn(a)ibr.cs.tu-bs.de To subscribe or unsubscribe via the World Wide Web, visit https://www.ibr.cs.tu-bs.de/mailman/listinfo/ibr-dtn or, via email, send a message with subject or body 'help' to ibr-dtn-request(a)ibr.cs.tu-bs.de You can reach the person managing the list at ibr-dtn-owner(a)ibr.cs.tu-bs.de When replying, please edit your Subject line so it is more specific than "Re: Contents of Ibr-dtn digest..." Today's Topics: 1. Re: interruption of transmission (Sebastian Schildt) 2. Re: interruption of transmission (Johannes Morgenroth) 3. Re: interruption of transmission (Sebastian Schildt) ---------------------------------------------------------------------- Message: 1 Date: Mon, 1 Jul 2013 13:28:32 +0200 From: Sebastian Schildt <schildt(a)ibr.cs.tu-bs.de> Subject: Re: [ibr-dtn] interruption of transmission To: "ibr-dtn(a)ibr.cs.tu-bs.de" <ibr-dtn(a)ibr.cs.tu-bs.de> Message-ID: <6194C931-4D9B-4DC0-9AB1-C5FAFE02A931(a)ibr.cs.tu-bs.de> Content-Type: text/plain; charset=us-ascii According to my understanding this value is only related to the TCP stack on the system. It can not be influenced by IBR-DTN (well maybe it could if you try setting some special option on the sockets that the TCP Convergence Layer uses, but AFAIK ibr-dtn doesn not do it). Basically TCP is a black box as far as the daemon is concerned: It stuffs bytes in, and sometimes get some bytes out. But TCP is fault-tolerant. When IBR-DTN puts bytes in and it has problems it will silently buffer them, trying to deliver them without telling the daemon about it. Only if after some time (on your system 15-20) seconds TCP still can not manage to deliver the bundle it will tell the daemon "Oops, something broke. The connection is gone". Only then IBR-DTN learns about the state of the connection and fragments the payload. So the timeout you are seeing is related to the TCP stack on your system. It might be possible to modify it, but I do not know how to achieve this. The time will be a combination of a defined number of TCP retries and the measured RTT used for the specific connection you are using. Sebastian Am 01.07.2013 um 12:32 schrieb Bruno Tavares <bmpt(a)ua.pt>: > Thank you for your quick answer Mr Schildt > > The thing is that if the interface is down for less than 15/20 seconds the bundle is not fragmented and it does not assume that the connection was lost for that period of time. after those 15/20 seconds in continues to send the bundle. If the interface is down for more than 20 seconds the bundle is fragmented and it is assumed that the connection was down. I just wanted to understand why this value and where can I change it. > > Best regards, > > Bruno Tavares > ________________________________________ > De: ibr-dtn-bounces(a)ibr.cs.tu-bs.de [ibr-dtn-bounces(a)ibr.cs.tu-bs.de] em nome de ibr-dtn-request(a)ibr.cs.tu-bs.de [ibr-dtn-request(a)ibr.cs.tu-bs.de] > Enviado: segunda-feira, 1 de Julho de 2013 11:00 > Para: ibr-dtn(a)ibr.cs.tu-bs.de > Assunto: Ibr-dtn Digest, Vol 36, Issue 1 > > Send Ibr-dtn mailing list submissions to > ibr-dtn(a)ibr.cs.tu-bs.de > > To subscribe or unsubscribe via the World Wide Web, visit > https://www.ibr.cs.tu-bs.de/mailman/listinfo/ibr-dtn > or, via email, send a message with subject or body 'help' to > ibr-dtn-request(a)ibr.cs.tu-bs.de > > You can reach the person managing the list at > ibr-dtn-owner(a)ibr.cs.tu-bs.de > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of Ibr-dtn digest..." > > > Today's Topics: > > 1. interruption of transmission (Bruno Tavares) > 2. Re: interruption of transmission (Sebastian Schildt) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Mon, 1 Jul 2013 08:26:02 +0000 > From: Bruno Tavares <bmpt(a)ua.pt> > Subject: [ibr-dtn] interruption of transmission > To: "ibr-dtn(a)ibr.cs.tu-bs.de" <ibr-dtn(a)ibr.cs.tu-bs.de> > Message-ID: > <90494CFA1222DC45A1855F79747890D8207D50C1(a)DBXPRD0210MB358.eurprd02.prod.outlook.com> > > Content-Type: text/plain; charset="us-ascii" > > Hello all > > After running some tests I noticed that if I break the connection between two nodes for small amount of time (let's say 4 or 5 seconds) and then connect again the bundle is not fragmented and the tcp connection does not go down. It assumes that no connection break happen and continues to deliver the bundle. > > I would like to know where I can find in the code where this small break of connection can be traced to make some debug. > > Can anyone help me? > > Best regards > > Bruno Tavares > > > > ------------------------------ > > Message: 2 > Date: Mon, 1 Jul 2013 10:45:21 +0200 > From: Sebastian Schildt <schildt(a)ibr.cs.tu-bs.de> > Subject: Re: [ibr-dtn] interruption of transmission > To: "ibr-dtn(a)ibr.cs.tu-bs.de" <ibr-dtn(a)ibr.cs.tu-bs.de> > Message-ID: <8739DF1D-FCE3-4E59-AAAE-676088E49766(a)ibr.cs.tu-bs.de> > Content-Type: text/plain; charset=us-ascii > > > > There should be a "Connection Down" even logged, when the TCP connection to another node breaks (I think even if you start the daemon with -v you should see that, even if you do not set a higher debug level). Before that IBR-DTN has no way of knowing that TCP hangs, because TCP is designed to play over small outages. Depending on the TCP configuration of your operating system, and the performance of the TCP connection until then, the TCP timeout could be up to a few minutes. > > > > > Sebastian > > > Am 01.07.2013 um 10:26 schrieb Bruno Tavares <bmpt(a)ua.pt>: > >> Hello all >> >> After running some tests I noticed that if I break the connection between two nodes for small amount of time (let's say 4 or 5 seconds) and then connect again the bundle is not fragmented and the tcp connection does not go down. It assumes that no connection break happen and continues to deliver the bundle. >> >> I would like to know where I can find in the code where this small break of connection can be traced to make some debug. >> >> Can anyone help me? >> >> Best regards >> >> Bruno Tavares >> >> -- >> !! 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://www.ibr.cs.tu-bs.de/mailman/listinfo/ibr-dtn. > > > > ------------------------------ > > -- > !! 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://www.ibr.cs.tu-bs.de/mailman/listinfo/ibr-dtn. > > End of Ibr-dtn Digest, Vol 36, Issue 1 > ************************************** > > ------------------------------ Message: 2 Date: Mon, 01 Jul 2013 13:41:46 +0200 From: Johannes Morgenroth <morgenroth(a)ibr.cs.tu-bs.de> Subject: Re: [ibr-dtn] interruption of transmission To: ibr-dtn(a)ibr.cs.tu-bs.de Message-ID: <51D16AFA.8030401(a)ibr.cs.tu-bs.de> Content-Type: text/plain; charset="iso-8859-1"; Format="flowed" Hello. That is not quite correct. The timeout noticed here depends on convergence layer specific keep-alive messages. http://tools.ietf.org/html/draft-irtf-dtnrg-tcp-clayer-02#section-5.5 By default this keepalive interval is set to 10 seconds and IBR-DTN closes a connection if there is no data for twice the interval. The "10" is set on every instantiation of the TCPConnection class. So search for this (and similar) lines of code and change it according to your needs. TCPConnection *obj = new TCPConnection(*this, node, client, 10); Kind regards, Johannes Morgenroth Am 01.07.2013 13:28, schrieb Sebastian Schildt: > According to my understanding this value is only related to the TCP stack on the system. It can not be influenced by IBR-DTN (well maybe it could if you try setting some special option on the sockets that the TCP Convergence Layer uses, but AFAIK ibr-dtn doesn not do it). > > Basically TCP is a black box as far as the daemon is concerned: It stuffs bytes in, and sometimes get some bytes out. But TCP is fault-tolerant. When IBR-DTN puts bytes in and it has problems it will silently buffer them, trying to deliver them without telling the daemon about it. Only if after some time (on your system 15-20) seconds TCP still can not manage to deliver the bundle it will tell the daemon "Oops, something broke. The connection is gone". Only then IBR-DTN learns about the state of the connection and fragments the payload. > > So the timeout you are seeing is related to the TCP stack on your system. It might be possible to modify it, but I do not know how to achieve this. The time will be a combination of a defined number of TCP retries and the measured RTT used for the specific connection you are using. > > Sebastian

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smallest openwrt router that can run ibr-dtn?
by Tom Sparks 15 Jul '13

15 Jul '13

I am wondering what is the smallest openwrt router that can run ibr-dtn? --- tom_a_sparks "It's a nerdy thing I like to do" Child of the Internet born 1983 PGP ID: A7EF6006 Please use ISO approved file formats excluding Office Open XML - http://www.gnu.org/philosophy/no-word-attachments.html Ubuntu wiki page https://wiki.ubuntu.com/tomsparks

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RE : static routes
by Bruno Tavares 14 Jul '13

14 Jul '13

Thank you for answering I just tried that and the bundle is not sent to trough node B to C. I will sent the configurations files I'm using. Thank you Regards Bruno Tavares ________________________________________ De: ibr-dtn-bounces(a)ibr.cs.tu-bs.de [ibr-dtn-bounces(a)ibr.cs.tu-bs.de] em nome de ibr-dtn-request(a)ibr.cs.tu-bs.de [ibr-dtn-request(a)ibr.cs.tu-bs.de] Enviado: sábado, 13 de Julho de 2013 9:16 Para: ibr-dtn(a)ibr.cs.tu-bs.de Assunto: Ibr-dtn Digest, Vol 36, Issue 6 Send Ibr-dtn mailing list submissions to ibr-dtn(a)ibr.cs.tu-bs.de To subscribe or unsubscribe via the World Wide Web, visit https://www.ibr.cs.tu-bs.de/mailman/listinfo/ibr-dtn or, via email, send a message with subject or body 'help' to ibr-dtn-request(a)ibr.cs.tu-bs.de You can reach the person managing the list at ibr-dtn-owner(a)ibr.cs.tu-bs.de When replying, please edit your Subject line so it is more specific than "Re: Contents of Ibr-dtn digest..." Today's Topics: 1. Re: Android implementation doubts (Johannes Morgenroth) 2. static routing (Bruno Tavares) 3. Re: Android implementation doubts (Guilherme Rolim) 4. Bundle expiration (Dimitrios Giotas) 5. Re: Bundle expiration (Sebastian Schildt) 6. Re: static routing (Stephan Rottmann) 7. Re: Bundle expiration (Sebastian Schildt) ---------------------------------------------------------------------- Message: 1 Date: Fri, 12 Jul 2013 16:38:00 +0200 From: Johannes Morgenroth <morgenroth(a)ibr.cs.tu-bs.de> Subject: Re: [ibr-dtn] Android implementation doubts To: ibr-dtn(a)ibr.cs.tu-bs.de Message-ID: <51E014C8.3070801(a)ibr.cs.tu-bs.de> Content-Type: text/plain; charset="iso-8859-1"; Format="flowed" Hello Guilherme, with the call to getNeighbors() you already were you want to be. The last missing step is to get the "endpoint" of the Nodes you got as list. The endpoint is a SingletonEndpoint object and contains the address you are looking for. Kind regards, Johannes Morgenroth Am 12.07.2013 01:39, schrieb Guilherme Rolim: > Hello, > > I'm coding a application for android based on the DTN Ping example, > however, I don't quite understand the use of some classes. For > instance, I am trying to get the neighbour list from the DTN app and > send a bundle to each neighbour but I don't know how to get their > addresses (something like dtn://example). I've managed to get the > neighbour list using the getDtnService() getNeighbors() methods from > the client, but there was no method to get their addresses. > > Could someone explain me the best way to do it? Also, is there any > document that may help me understand the dtn api classes? > > Thanks in advance, > Guilherme rolim > > > -- > !! 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://www.ibr.cs.tu-bs.de/mailman/listinfo/ibr-dtn.

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Re: [ibr-dtn] Bundle expiration
by Sebastian Schildt 13 Jul '13

13 Jul '13

If all you want to acheive is a limited lifetime of 15 min for a bundle, you can use the --lifetime parameter in dtnping or dtnsend, i.e. echo "Hello" | dtnsend --lifetime 900 dtn://dst.dtn/app sends a bundle with payload "Hello" and a lifetime of 15 min. After 15 min all DTN nodes whos till have that bundle in storage will delete it. Noramlly you do not need to set anzthing in the configuratin, because the lifetime is a per bundle setting. If you set the limit_lifetime option, a node would reject bundles sent to him, whose remaining lifetime is larger. So in many normal use case you do not want this (only as a safeguard perhaps). Moreso for the predated option, which can maybe protect you against misconfigured clocks or "weird" bundles, but it also not needed normaly. What you probably want is the lifetime setting for an indivudal bundle. Sebastian Am 12.07.2013 um 23:40 schrieb Dimitrios Giotas <dimigiotas(a)gmail.com>: > Thank you for your reply Sebastian. > > However I still don't get the difference between timestamp and lifetime. As far as I can understand they both signify the time it has passed since the creation of the bundle, so is there really a difference? > > If I wanted to bundle to be dropped after 15 minutes which parameter do I alter? > I think the lifetime is the correct one, but I can't say for sure since I don't know the timestamp concept. > > Regards, > Dimitris > > > > > On Sat, Jul 13, 2013 at 12:11 AM, Sebastian Schildt <schildt(a)ibr.cs.tu-bs.de> wrote: > Ah if I am not mistaken the limit_predated means it will reject bundles whose timestamps is to far (more than allowed by the parameter) in the future. So it seems "pre"dated is not a good word for this, as it rather means "post"dated. > > limit_lifetime does just what it says on the can: Bundle whose lifetime is greater will be rejected. This is rather a safeguard against unfortunate "mishaps". Once one of our students accidentally managed to generate lots of bundles with a lifetime of several years and we had a real hard time getting them out of our network and thus this feature was born :) > > Sebastian > > Am 12.07.2013 um 23:03 schrieb Dimitrios Giotas <dimigiotas(a)gmail.com>: > > > Hello, > > > > The difference between the limit_predated_timestamp and the limit_lifetime is quite unclear to me. > > > > Would anyone please explain the difference, or better yet the meaning of limit_predated_timestamp. > > > > Thank you. > > > > Regards, > > Dimitris. > > -- > > !! 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://www.ibr.cs.tu-bs.de/mailman/listinfo/ibr-dtn. > >

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static routing
by Bruno Tavares 12 Jul '13

12 Jul '13

Hello. I am trying to set up a simple network using static routes. I want to have three nodes A,B and C. When I send a bundle from A to C I want it to pass trough B and not directly to C. Is is possible ? I tried setting up the conf file to do this but the bundle is sent to B and C directly from A. On node A I have this configuration routing=default route1= dtn://drivein254.dtn dtn://drivein253.dtn //on static routing rules static1_address = 20.0.0.253 # the node has the address 10.0.0.5 static1_port = 4556 # accept bundles on port 4556 static1_uri = dtn://drivein253.dtn # eid of the node is "dtn://node-five.dtn" static1_proto = tcp # reachable over TCP static1_immediately = yes # connect immediately to this node Thank you Regards, Bruno Tavares

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Bundle expiration
by Dimitrios Giotas 12 Jul '13

12 Jul '13

Hello, The difference between the limit_predated_timestamp and the limit_lifetime is quite unclear to me. Would anyone please explain the difference, or better yet the meaning of limit_predated_timestamp. Thank you. Regards, Dimitris.

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IBR-DTN and DTN2 compatibility
by Dimitrios Giotas 12 Jul '13

12 Jul '13

Hello, I was wondering if there are other commands, except dtnping and dtnsend/recv, that are interoperable between IBR and DTN2. To be more specific, is there a way to copy a file from IBR to DTN2 and vice versa? I was thinking something between dtnoutbox/inbox and dtncp/dtncpd, but so far I have failed to do so. Thank you. Regards, Dimitris

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ibr-dtn and dtn2 data exchange
by Dimitrios Giotas 10 Jul '13

10 Jul '13

Hello, I am tryng to use dtnsend/recv between a laptop that runs ibr and another that runs dtn2. When I use the following commads On IBR : dtnsend dtn://hp/filetransfer /home/ibrdtn/... On Dtn2 : dtnrecv dtn://dell/filetransfer I get the following error in the dtn2 daemon : [1373409728.490016 /dtn/bundle/extblock/aeb info] consume() begin [1373409728.490091 /dtn/bundle/extblock/aeb info] oasys::Time now(): 3315161066 [1373409728.490128 /dtn/bundle/extblock/aeb info] Bundle Age: 2576 [1373409728.490157 /dtn/bundle/extblock/aeb info] consume() end [1373409728.490493 /dtn/bundle/protocol info] handle_bundle_received: begin [1373409728.490562 /S10 info] 2013-07-09 22:42:08,1373409728.490538,dtn://dell,RX,4,dtn://hp/routing,426717728.4,dtn://dell/routing,60,, 10.0.0.228:4556,,,0.000000,,0,link [1373409728.490699 /dtn/bundle/daemon info] BUNDLE_RECEIVED bundle id 36 [dtn://hp/routing -> dtn://dell/routing 4 byte payload] prevhop dtn://hp (74 bytes recvd) [1373409728.490745 /dtn/bundle/daemon info] handle_bundle_received: validating bundle: calling BlockProcessors? [1373409728.490771 /dtn/bundle/protocol info] BundleProtocol::validate begin [1373409728.490794 /dtn/bundle/protocol info] validating each individual blocks [1373409728.490824 /dtn/bundle/protocol info] BundleProtocol::validate end [1373409728.490854 /dtn/bundle/expiration info] adding bundle to pending list [1373409728.505117 /dtn/bundle/expiration info] [AEB]: AgeBlock exists. [1373409728.505217 /dtn/bundle/expiration info] [AEB]: expiring in 4294964780 seconds [1373409728.505266 /dtn/bundle/expiration warning] scheduling IMMEDIATE expiration for bundle id 36: [expiration 60, creation time 426717728.4, offset 946684800, now 1373409728.505098] [1373409728.505458 /dtn/bundle/daemon info] BUNDLE_EXPIRED bundle id 36 [dtn://hp/routing -> dtn://dell/routing 4 byte payload] Basically it immediately deletes the bundle, because of faulty timestamp if I get this right. Is this a problem on IBR's end or should I consult the dtn2 forum? Thank you Regards Dimitris Giotas

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Re: [ibr-dtn] interruption of transmission
by Sebastian Schildt 01 Jul '13

01 Jul '13

According to my understanding this value is only related to the TCP stack on the system. It can not be influenced by IBR-DTN (well maybe it could if you try setting some special option on the sockets that the TCP Convergence Layer uses, but AFAIK ibr-dtn doesn not do it). Basically TCP is a black box as far as the daemon is concerned: It stuffs bytes in, and sometimes get some bytes out. But TCP is fault-tolerant. When IBR-DTN puts bytes in and it has problems it will silently buffer them, trying to deliver them without telling the daemon about it. Only if after some time (on your system 15-20) seconds TCP still can not manage to deliver the bundle it will tell the daemon "Oops, something broke. The connection is gone". Only then IBR-DTN learns about the state of the connection and fragments the payload. So the timeout you are seeing is related to the TCP stack on your system. It might be possible to modify it, but I do not know how to achieve this. The time will be a combination of a defined number of TCP retries and the measured RTT used for the specific connection you are using. Sebastian Am 01.07.2013 um 12:32 schrieb Bruno Tavares <bmpt(a)ua.pt>: > Thank you for your quick answer Mr Schildt > > The thing is that if the interface is down for less than 15/20 seconds the bundle is not fragmented and it does not assume that the connection was lost for that period of time. after those 15/20 seconds in continues to send the bundle. If the interface is down for more than 20 seconds the bundle is fragmented and it is assumed that the connection was down. I just wanted to understand why this value and where can I change it. > > Best regards, > > Bruno Tavares > ________________________________________ > De: ibr-dtn-bounces(a)ibr.cs.tu-bs.de [ibr-dtn-bounces(a)ibr.cs.tu-bs.de] em nome de ibr-dtn-request(a)ibr.cs.tu-bs.de [ibr-dtn-request(a)ibr.cs.tu-bs.de] > Enviado: segunda-feira, 1 de Julho de 2013 11:00 > Para: ibr-dtn(a)ibr.cs.tu-bs.de > Assunto: Ibr-dtn Digest, Vol 36, Issue 1 > > Send Ibr-dtn mailing list submissions to > ibr-dtn(a)ibr.cs.tu-bs.de > > To subscribe or unsubscribe via the World Wide Web, visit > https://www.ibr.cs.tu-bs.de/mailman/listinfo/ibr-dtn > or, via email, send a message with subject or body 'help' to > ibr-dtn-request(a)ibr.cs.tu-bs.de > > You can reach the person managing the list at > ibr-dtn-owner(a)ibr.cs.tu-bs.de > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of Ibr-dtn digest..." > > > Today's Topics: > > 1. interruption of transmission (Bruno Tavares) > 2. Re: interruption of transmission (Sebastian Schildt) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Mon, 1 Jul 2013 08:26:02 +0000 > From: Bruno Tavares <bmpt(a)ua.pt> > Subject: [ibr-dtn] interruption of transmission > To: "ibr-dtn(a)ibr.cs.tu-bs.de" <ibr-dtn(a)ibr.cs.tu-bs.de> > Message-ID: > <90494CFA1222DC45A1855F79747890D8207D50C1(a)DBXPRD0210MB358.eurprd02.prod.outlook.com> > > Content-Type: text/plain; charset="us-ascii" > > Hello all > > After running some tests I noticed that if I break the connection between two nodes for small amount of time (let's say 4 or 5 seconds) and then connect again the bundle is not fragmented and the tcp connection does not go down. It assumes that no connection break happen and continues to deliver the bundle. > > I would like to know where I can find in the code where this small break of connection can be traced to make some debug. > > Can anyone help me? > > Best regards > > Bruno Tavares > > > > ------------------------------ > > Message: 2 > Date: Mon, 1 Jul 2013 10:45:21 +0200 > From: Sebastian Schildt <schildt(a)ibr.cs.tu-bs.de> > Subject: Re: [ibr-dtn] interruption of transmission > To: "ibr-dtn(a)ibr.cs.tu-bs.de" <ibr-dtn(a)ibr.cs.tu-bs.de> > Message-ID: <8739DF1D-FCE3-4E59-AAAE-676088E49766(a)ibr.cs.tu-bs.de> > Content-Type: text/plain; charset=us-ascii > > > > There should be a "Connection Down" even logged, when the TCP connection to another node breaks (I think even if you start the daemon with -v you should see that, even if you do not set a higher debug level). Before that IBR-DTN has no way of knowing that TCP hangs, because TCP is designed to play over small outages. Depending on the TCP configuration of your operating system, and the performance of the TCP connection until then, the TCP timeout could be up to a few minutes. > > > > > Sebastian > > > Am 01.07.2013 um 10:26 schrieb Bruno Tavares <bmpt(a)ua.pt>: > >> Hello all >> >> After running some tests I noticed that if I break the connection between two nodes for small amount of time (let's say 4 or 5 seconds) and then connect again the bundle is not fragmented and the tcp connection does not go down. It assumes that no connection break happen and continues to deliver the bundle. >> >> I would like to know where I can find in the code where this small break of connection can be traced to make some debug. >> >> Can anyone help me? >> >> Best regards >> >> Bruno Tavares >> >> -- >> !! 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://www.ibr.cs.tu-bs.de/mailman/listinfo/ibr-dtn. > > > > ------------------------------ > > -- > !! 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://www.ibr.cs.tu-bs.de/mailman/listinfo/ibr-dtn. > > End of Ibr-dtn Digest, Vol 36, Issue 1 > ************************************** > >

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interruption of transmission
by Bruno Tavares 01 Jul '13

01 Jul '13

Hello all After running some tests I noticed that if I break the connection between two nodes for small amount of time (let's say 4 or 5 seconds) and then connect again the bundle is not fragmented and the tcp connection does not go down. It assumes that no connection break happen and continues to deliver the bundle. I would like to know where I can find in the code where this small break of connection can be traced to make some debug. Can anyone help me? Best regards Bruno Tavares

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