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

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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