Explaination of new feature: It would be great if iperf3 can support fragmentation. User can specify the size of each packet and base on the mtu of the interface, the packet gets fragmented.

Justification of new feature: Currently there is no linux test tools that can do TCP fragmentation. If fragmentation is needed for TCP, you would have to use a router in between the client and server to fragment the packet. If linux test tool can do that, there would be less configuration on the topology.

project team discussed this, and decided this is better done using ping, so marking 'wont fix'