We are working on establishing a tunnel for MAC protocol design using tunnel.py given as example in GNU Radio but are unable to receive ping reply from the other node.
We created tun/tap interface using ./tunnel.py -f 990M and ipconfig 192.168.200.1 on Machine A connected to N210 series of USRP.
and ./tunnel.py -f 990M and ifconfig 192.168.200.2 on machine B.
1. Now on pinging machine B from A we can see ping packets being sent to B by A using wireshark, but there is no reply on node A.
2. We went into details and saw there were ARQ requests from B repetitively.
I manually added the mac address to update the table.
Now ARQ request ceased to exist but still there were no replies on A.
3. Since we knew the Packaging details of ICMP we read the packets being received by B and found the exact source address of A from the frame. It means message have been successfully decoded by the destination and it knows whom to reply for the ping but still I don't find any reception confirmation on source side.
What may be the possible problems?USRP antenna gain?Packets collision?
In short we are unable to use tunnely.py and are seeking for possible causes.
Jay Prakash
Senior Undergraduate