Subject: [dtn-users] movement of data bundle and administrative bundle in different communication medium.

From: asif <[email-masked]>
Date: Tue, 05 Nov 2013 16:55:58 +0900

Hi,

I want to do an experiment where I will send the data bundles through
vehicular opportunistic network. where bundles will be physically carried
over vehicles. But the acknowledgement bundles will be sent back through
SMS. http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6572625

Is it supported by DTN2?

Any clue how?

Asifur Rahman, Kyushu University, Japan

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From: "Ivancic, William D. (GRC-RHN0)" <[email-masked]>
Date: Tue, 5 Nov 2013 13:15:55 +0000

Asifur,

I haven't really played with DTN setup in some time. The short answer is
probably yes for a very controlled demonstration with a sort of static
routing.  In a real-world deployed network, it probably gets much more
complicated.

Can you be more specific.

Are these hop-by-hop acknowledgments or end-to-end?
Are you requesting custody transfer?
What type of routing protocol are you using in the vehicle opportunistic
network (flooding or limited flooding)?

Will

******************************
William D. Ivancic
Phone 216-433-3494
Fax 216-433-8705
Networking Lab 216-433-2620
Mobile 440-503-4892
http://roland.grc.nasa.gov/~ivancic

On 11/5/13 2:55 AM, "asif" <[email-masked]> wrote:

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From: asif <[email-masked]>
Date: Thu, 14 Nov 2013 15:56:36 +0900

William,

I have not seen previous response in the thread. So sending it again.

I want to send the data bundle hop-by-hop. But the ACK bundle will reach
the sender directly from the final receiver. The custody transfer of the
data bundle will be as usual. But the custody control of the ACK bundle
will be over SMS.

I have a publication with the concept. Is attached for your convenience.

Regards

Asif

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From: Caini Carlo <[email-masked]>
Date: Thu, 14 Nov 2013 11:47:17 +0100

Dear Asif,
     I have given a glance at your paper. Frankly speaking, while the 
RFC4838 description of Custody is an example of clarity, your text is 
not. In my opinion this largely depends on the use of ambiguous terms 
to indicate the various kind of acknowledgments instead of the terms 
stated in RFC 4838.
In particular RFC4838 defines two kind of administrative bundles, the 
"bundle status reports" and the "custody signals".

>
>3.6.2.  Administrative Records: Bundle Status Reports and Custody
>
>
>
>         Signals
>
>
>
>    Administrative records are used to report status information or error
>    conditions related to the bundle layer.  There are two types of
>    administrative records defined:  bundle status reports (BSRs) and
>    custody signals.

In particular custody signals, always sent to the "custodian" EID, 
have this use:

>When a node accepts custody for a bundle that contains the Custody
>    Transfer Requested option, a Custody Transfer Accepted Signal is sent
>    by the bundle layer to the Current Custodian EID contained in the
>    primary bundle block.
Concerning BSR, we have, among the others, two kinds of informative 
ACKs, one hop-by-hop, the other end-to-end. Note that DTN nodes can 
be asked to send these BSRs, or not by the source. These ACKs, as all 
BSR, are sent to the "reply to" EID, which may be, or may be not, the source.

>Bundle Reception - sent when a bundle arrives at a DTN node.
>      Generation of this message may be limited by local policy.
>Bundle Delivery - sent from a final recipient's (destination) node
>      when a complete ADU comprising sent bundles containing Report When
>      Bundle Delivered options is consumed by an application.

This said, let me consider this excerpt from your text (Fig.5 helps 
the text comprehension):
>According to reference [3], a bundle transfer process from
>Point A to Point C can be explained by Fig. 5. Arrows in solid
>lines represent the movement of data bundle,

OK.

>arrows in dashed
>line represent the movement of custody control transfer
>acknowledgement of data bundle,

likely you mean the "Custody Transfer Accepted Signals"

>arrows in long dashed line
>represent received acknowledgement bundle from the
>destination node,

do you mean "BSR reception" or "BSR delivery"? I would guess the 
second from the context, but I am not sure.

>arrows in dotted line represent the movement
>of custody control transfer acknowledgement of received
>acknowledgement bundle.

Custody signals always refer to data bundles. I cannot understand this part.

Please consider my comments not aimed at criticizing your work, but 
just at pointing out to all subscribers the importance of a rigorous 
use of RFC terms.

Yours sincerely,
     Carlo Caini