Hi Thomas,

An alternative would be to use a radio emulator like the Extended Mobile Adhoc Network Emulator (EMANE) to emulate VHF radio properties at the phy layer, and use UDP convergence on IBR-DTN on top of it. I use the combination of EMANE and IBR-DTN on the Common Open Research Emulator (CORE) platform to emulate a variety of networks running DTN.

Regards, Vijay

On Mon, Jan 23, 2017 at 8:52 PM, Thomas Halwax < thomas.halwax@technikum-wien.at> wrote:

Hi Stephan,

thanks for your response. I will have a look at the code. Any snippets from your attic are highly welcome :-)

Thanks and best regards Thomas

...

Am 23.01.2017 um 11:31 schrieb Stephan Rottmann <

rottmann@ibr.cs.tu-bs.de>:

...

Hi Thomas,

at the moment, there doesn't exist something like that (as far as I know). You might try to create a new CL based on the datagram CL, that could be "dgram:<yourVHFradio>" or similar.

Once I had something similar for a point-to-point serial connection, maybe I'll find that and can see if it's still compatible...

Best regards, Stephan

Am Sonntag, den 22.01.2017, 16:22 +0100 schrieb Thomas Halwax:

...

Hi,

for my Bachelor Paper I’d like to use IBR-DTN over VHF radios. These devices have a RS-232 serial interface. I know there is a AX.25 convergence layer for DTN2. Is there something similar for IBR-DTN or do you have any suggestions?

Thanks in advance, Thomas

-- !! 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@ibr.cs.tu-bs.de !! or look at https://mail.ibr.cs.tu-bs.de/listinfo/ibr-dtn.

Hi Vijay,

thank you again for your suggestion. I created a lab with two DTN nodes using the UDPDatagramm convergence layer. My EMANE emulation tries to act like a SINCGARS (Single Channel Ground and Air Radio System) tactical radio. The throughput at the phy layer is limited to 9000 bits/s. While the DTN detection and transmission of very small files (up to 512 bytes) works good most of the time, transmission of larger files often fails. I guess (because I don’t know) this is due to the heavy traffic on the emulated radio channel that leads to a lot of dropped packets.

To work around this issue I’d like to tune the parameters of the DatagramConnection, DatagramService and UDPDatagramService classes.

UDPDatagramService params I’d like to tune:

* flowcontrol (STOPNWAIT instead of SLIDING_WINDOW) * initial_timeout (1000ms instead of 50ms)

To be honest I’ve got two questions to the experts:

1) do you think tuning these params will help? 2) is it possible to tune these params using the external config file or do I have to recompile the code?

Thanks in advance!

Best regards, Thomas

Am 23.01.2017 um 17:40 schrieb Vijayasarathy Rajagopalan shanv82@gmail.com:

Hi Thomas,

An alternative would be to use a radio emulator like the Extended Mobile Adhoc Network Emulator (EMANE) to emulate VHF radio properties at the phy layer, and use UDP convergence on IBR-DTN on top of it. I use the combination of EMANE and IBR-DTN on the Common Open Research Emulator (CORE) platform to emulate a variety of networks running DTN.

Regards, Vijay