[Ndn-interest] Interest Order Maintaining

Burke, Jeff jburke at remap.UCLA.EDU
Sat Feb 14 08:03:45 PST 2015


As Junxiao says, reordering of data is necessary and, for example, is handled for video (and audio) in both NDNVideo<https://github.com/named-data/ndnvideo> and ndnrtc<https://github.com/remap/ndnrtc>.  NDNVideo has a longer playout buffer and thus can handle more out of order packets without impacting playback;  ndnrtc is designed with a small buffer for real-time conversations but also handles reordering of data packets. (In these and many other applications, interest retransmissions in the case of dropped packets also have to be handled.)

In these apps, interest reordering is not performed at the producer; it is simpler to just publish data to an application memory cache (done in ndnrtc) or ndn repository (done in NDNVideo), and let that store respond to whatever interests come in, regardless of ordering.  So, only the consumer has to reorder data.  This might not be the case in some applications that use Interest for control and might worried about the time the interests were issued at the source.

There is active work to generalize APIs that handle ordering and retransmission, e.g., Ilya Moiseenko's work presented at NDNComm 2014<http://www.caida.org/workshops/ndn/1409/>.

Jeff

From: Junxiao Shi <shijunxiao at email.arizona.edu<mailto:shijunxiao at email.arizona.edu>>
Date: Sat, 14 Feb 2015 08:21:08 -0700
To: Nitinder Mohan <nitinder1369 at iiitd.ac.in<mailto:nitinder1369 at iiitd.ac.in>>
Cc: "ndn-interest at lists.cs.ucla.edu<mailto:ndn-interest at lists.cs.ucla.edu>" <ndn-interest at lists.cs.ucla.edu<mailto:ndn-interest at lists.cs.ucla.edu>>
Subject: Re: [Ndn-interest] Interest Order Maintaining

Hi Nitinder

NDN network does not guarantee in order delivery. An Interest could also be delivered to the producer multiple times.
The end consumer, either implemented in app or in library, should handle out-of-order packets. This situation is no different from IP.

Yours, Junxiao
This is a correction to a previous answer. It replaces all prior answers.

On Sat, Feb 14, 2015 at 3:50 AM, Nitinder Mohan <nitinder1369 at iiitd.ac.in<mailto:nitinder1369 at iiitd.ac.in>> wrote:
Hello All!

A curious question comes to my mind regarding routing strategy in NDN.

Let us assume that there is one consumer and one producer in a network consisting of myriad of routers. If a consumer issues continuous interests for different data packets from the same producer, is it guaranteed that the Interest packets will arrive at producer in the same order as in which they were published?

I understand that NDN follows multipath routing and later selects paths from its PIT entry according to performance of returning data. But wouldn't consecutive interests be sent on the same interface presuming there is no change in the network.

Thanks and Regards

Nitinder Mohan
MTech (CE) IIIT Delhi
http://home.iiitd.edu.in/~nitinder1369/

_______________________________________________
Ndn-interest mailing list
Ndn-interest at lists.cs.ucla.edu<mailto:Ndn-interest at lists.cs.ucla.edu>
http://www.lists.cs.ucla.edu/mailman/listinfo/ndn-interest


_______________________________________________ Ndn-interest mailing list Ndn-interest at lists.cs.ucla.edu<mailto:Ndn-interest at lists.cs.ucla.edu> http://www.lists.cs.ucla.edu/mailman/listinfo/ndn-interest
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.lists.cs.ucla.edu/pipermail/ndn-interest/attachments/20150214/4e9e57af/attachment.html>


More information about the Ndn-interest mailing list