Censorship analysis idea for Coverage of Attention List UDP Traffic Censorship in Iran
Based on the previous research, Iran has a 3 level censorship for UDP traffic. However, we are still in the dark about how widespread this kind of censorship is.
Here is the idea about this experiment:
- traceroute to a host with udp packet to determine hops to reach the remote host
- send a non-censored udp packet at reachable ttl - 1 and see if there is a icmp ttl exhausted response
- send a censored udp packet at reachable ttl - 1 from the same source port to the same destination port and see if there is a icmp ttl exhausted response
- send a non-censored udp packet at reachable ttl - 1 from the same source port to the same destination port and see if there is a icmp ttl exhausted response
- repeat this process a few times for each host and repeat for every host on internet
if the remote is impacted by compete udp block, then
- icmp ping at step 1 would work
- 2, 3, 4 step does not receive an icmp reply
if the remote is impacted by partial udp block, then
- icmp ping at step 1 would work
- 2 step receive an icmp reply
- 3,4 step does not receive an icmp reply
if the remote is not impacted by udp block, then
- icmp ping at step 1 would work
- 2, 3, 4 step receive icmp reply