[ndnSIM] Satisfy Interests with more than one producer

[Alex Afanasyev]

Hi Amin,

Let me clarify a little bit with a small example:

Consumer --- Router ----- Producer1
               |
               +--------- Producer2

Assuming ns3::ndn::fw::Flooding strategy, Interests from the Consumer will reach both Producer1 and Producer2, and they both will send back a content object packet.

Router, receiving the first packet (depending on the topology, could be from Producer1 or Producer2) will forward it to the consumer and remove* the PIT entry.  When the second content object arrives to the Router (not the consumer), it will be discarded by the router, as unsolicited.   (I would not call this as a drop, since it is relatively high-level decision to not forward the specific packet.)

* PIT entry can be immediately removed (by default), or scheduled for removal within a short time interval (PitEntryPruningTimout).  In either case, an extra content object will be discarded.

---
Alex

On Mar 31, 2013, at 12:02 PM, Amin Karami <amin at ac.upc.edu> wrote:

> In case of ns3::ndn::fw::Flooding, we will have several drops. Because when a consumer receives desired content from first sender/producer, consumer will drop other same contents. Yes? because the desired Interest has been satisfied and removed from PIT.
> 
> 
> /Amin
> 
> 
> On 03/31/2013 08:42 ب.ظ, Alex Afanasyev wrote:
>> Hi Amin,
>> 
>> I is possible, but it depends on the forwarding strategy to deliver Interests to different producers.  For example, if you choose ns3::ndn::fw::BestRoute, then Interests will only be delivered over the "shortest-metric" path and some of the producers will never see the Interests.   If you use ns3::ndn::fw::Flooding, then all of the producers will receive Interests and it would depend on network topology (delays/losses) content object from which exactly producer will reach the consumer.
>> 
>> In case if you have several consumers, depending on topology and forwarding strategy, they may be getting content objects from different producers.
>> 
>> If you want only some Interests be satisfied by one producers and other by another, you may need to amend ndn::Producer implementation (or better create a new custom Producer app) by adding the appropriate logic.
>> 
>> ---
>> Alex
>> 
>> On Mar 31, 2013, at 11:35 AM, Amin Karami <amin at ac.upc.edu> wrote:
>> 
>>> Hi friends,
>>> Is it possible to satisfy sent Interests from a consumer with more than one producer?
>>> for example, does the following code work correctly to satisfy Interests in /dst1 namespace with three producers?
>>>   ndnGlobalRoutingHelper.AddOrigins ("/dst1", producer1);
>>>   producerHelper.SetPrefix ("/dst1");
>>>   producerHelper.Install (producer1);
>>>  
>>>   ndnGlobalRoutingHelper.AddOrigins ("/dst1", producer2);
>>>   producerHelper.SetPrefix ("/dst1");
>>>   producerHelper.Install (producer2);
>>> 
>>>   ndnGlobalRoutingHelper.AddOrigins ("/dst1", producer3);
>>>   producerHelper.SetPrefix ("/dst1");
>>>   producerHelper.Install (producer3);
>>> 
>>> 
>>> Best Regards,
>>> /Amin
>>> 
>>> _______________________________________________
>>> ndnSIM mailing list
>>> ndnSIM at lists.cs.ucla.edu
>>> http://www.lists.cs.ucla.edu/mailman/listinfo/ndnsim
>> 
> 
> 
> -- 
> 
> Best Regards,
> 
> =======================================================
> Amin Karami, PhD student in Computer Architecture Department (DAC) at
> the Universitat Politècnica de Catalunya Barcelona Tech (UPC)
> 
> e-mail: amin at ac.upc.edu | UPC-Campus Nord., Office: C6-E102
> phone: +34 93 40 11 638 | Jordi Girona, 1-3
>                                            | 08034 Barcelona - SPAIN
> WWW: http://personals.ac.upc.edu/amin/
> =======================================================
> 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.lists.cs.ucla.edu/pipermail/ndnsim/attachments/20130331/7c9526c6/attachment.html>