[ndnSIM] Tracing RTT values of PIT entries

Amin Karami amin at ac.upc.edu
Sun Dec 1 13:03:54 PST 2013


Hi Alex,
It means that, we can not print all the RTT time for all satisfied PIT 
entries?

/Amin

On 12/01/2013 09:46 ب.ظ, Alex Afanasyev wrote:
> Hi Amin,
>
>  From what I can guess, other PIT entries are simply getting satisfied. The three that you're seeing is basically a "pipeline" based on bandwidth-delay-product in the system.
>
> ---
> Alex
>
> On Nov 27, 2013, at 4:25 AM, Amin Karami <amin at ac.upc.edu> wrote:
>
>> Hi Alex,
>> I design a simple scenario as follows:
>> c1--->
>> c2---> R3 ----> R2 ----> p1
>> c3--->
>>
>> c1,c2 and c3 are connected to R3. In the first 3 seconds, just c1 sends Interest packets. When I printed the RTT values of PIT entries in R3, I face with below output:
>>
>> 1    R3    PIT Size: 3
>> =========
>> /dst1/%00%01P
>> mean of RTT: 0.00966371, Variance of RTT: 0.000361557
>> Prefix: /dst1/%00%01P
>> In: dev[10]=net(0,0-10)
>> Out: dev[10]=net(1,9-10)
>> Nonces: 2647520711
>> =========
>> /dst1/%00%01R
>> mean of RTT: 0.00966371, Variance of RTT: 0.000361557
>> Prefix: /dst1/%00%01R
>> In: dev[10]=net(0,0-10)
>> Out: dev[10]=net(1,9-10)
>> Nonces: 3120749414
>> =========
>> /dst1/%00%01Q
>> mean of RTT: 0.00966371, Variance of RTT: 0.000361557
>> Prefix: /dst1/%00%01Q
>> In: dev[10]=net(0,0-10)
>> Out: dev[10]=net(1,9-10)
>> Nonces: 315221540
>>
>> 2    R3    PIT Size: 3
>> =========
>> /dst1/%00%02%C6
>> mean of RTT: 0.0100666, Variance of RTT: 0.000979842
>> Prefix: /dst1/%00%02%C6
>> In: dev[10]=net(0,0-10)
>> Out: dev[10]=net(1,9-10)
>> Nonces: 2858765059
>> =========
>> /dst1/%00%02%C7
>> mean of RTT: 0.0100666, Variance of RTT: 0.000979842
>> Prefix: /dst1/%00%02%C7
>> In: dev[10]=net(0,0-10)
>> Out: dev[10]=net(1,9-10)
>> Nonces: 629247679
>> =========
>> /dst1/%00%02%C8
>> mean of RTT: 0.0100666, Variance of RTT: 0.000979842
>> Prefix: /dst1/%00%02%C8
>> In: dev[10]=net(0,0-10)
>> Out: dev[10]=net(1,9-10)
>> Nonces: 2514818005
>>
>>
>> The rate of sending Interests is 400 per second for c1. As you seen, in each second, just 3 entries accommodate in PIT for routing purpose in FIB. What is the problem? Where is other about 397 Interest packets?
>>
>> My implementation for printing RTT values are:
>>
>> void PeriodicStatsPrinter (Ptr<Node> node, Time next)
>> {
>> Ptr<ndn::Pit> pit = node->GetObject<ndn::Pit> ();
>>   std::cout << Simulator::Now ().ToDouble (Time::S) << "\t"
>>             << Names::FindName (node) << "\t"
>>             << "PIT Size: " << pit->GetSize () << "\t"
>> for (Ptr<ndn::pit::Entry> entry = pit->Begin (); entry != pit->End (); entry = pit->Next (entry))
>>   {
>>     std::cout << "=========" << std::endl;
>>     std::cout << entry->GetPrefix () << std::endl;
>>     for (FaceMetricContainer::type::index<i_nth>::type::iterator metric = entry->GetFibEntry()->m_faces.get<i_nth> ().begin(); metric != entry->GetFibEntry()->m_faces.get<i_nth> ().end(); metric++)
>>     {
>>     std::cout << "mean of RTT: " << metric->GetSRtt ().ToDouble(Time::S) << ", Variance of RTT: " << metric->GetRttVar().ToDouble(Time::S) << "\n";
>>     }
>>      std::cout << *entry << std::endl;
>>   }
>>   Simulator::Schedule (next, PeriodicStatsPrinter, node, next);
>> }
>>
>>
>>
>> Best Regards,
>> Amin
>>
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>> ndnSIM at lists.cs.ucla.edu
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