[ndnSIM] Missing HopCountTag in Data Packets

[Susmit]

Hi All,

I have an ndnSIM topology with one producer, multiple consumers and
intermediate nodes.  I am trying to get the hop count for incoming
data packets at the consumers.

Below are the code and the trace for a single Interest packet.
I confirmed that I am getting data from a different node (node 64)
than the consumer (node 54), so the reply is not from local
cache/local producer.

This is my code  for consumer::onData

________________________ Code  ______________________________________

    void
    onData(const ndn::Interest& interest, const ndn::Data& data)
    {
        auto ID = ns3::Simulator::GetContext();
        auto now = ns3::Simulator::Now().To(ns3::Time::S);

         int hopCount = 0;
         auto hopCountTag = data.getTag<ndn::lp::HopCountTag>();
         if (hopCountTag != nullptr) {
            hopCount = *hopCountTag;
            std::cout << "Hop count: " << *hopCountTag << std::endl;
          }
        else {
            std::cout << "Packet tag doesn't exist for " <<
data.getName() <<  std::endl;
        }
        std::cout << "Time: " << now << ",node:" << ID  <<  "
Consumer:onData"   << ",Data Name "  << data.getName() << ",Hop Count
" << hopCount << std::endl;

        ..............
    }
__________________________ Trace ____________________________________




1. Scheduling /cmip5/app/zg_Amon_EC-EARTH_rcp45_r6i1p1_200601-205012.nc/%00%00
at node 54 at time 1446227878 nonce 1495198176

2. Time: +1.44622787799999999995,node:54, Consumer:delayedInterest,
Interest Name /cmip5/app/zg_Amon_EC-EARTH_rcp45_r6i1p1_200601-205012.nc/%00%00

3. Time :+1.44635877299999999996 node:64, Producer::OnInterest,
Received interest:
/cmip5/app/zg_Amon_EC-EARTH_rcp45_r6i1p1_200601-205012.nc/%00%00 Nonce
: 1495198176

4. Packet tag doesn't exist for
/cmip5/app/zg_Amon_EC-EARTH_rcp45_r6i1p1_200601-205012.nc/%00%00/1495198176

5. Time: +1.57473100799999999997,node:54, Consumer:onData, Data Name
/cmip5/app/zg_Amon_EC-EARTH_rcp45_r6i1p1_200601-205012.nc/%00%00/1495198176,Hop
Count 0


I am not sure if I am missing something.

Thanks for your help.

-- 
Regards,
Susmit.