Today I invest my time in adding a new option for netsend to introduce an artificial read() delay in the receiver path. The new option can be enabled via:

netsend -v loudish -B 10,1 -b 250 -s SO_RCVBUF 1 tcp receive

The options states that the receiver should initial block for 10 seconds and then read 250 byte chunks with a delay of one second: -B 10,1. If you waive the initial delay you can also skip the coma separated list and hand over only one argument, e.g. -b 1. This will delay the read() operation with a one second delay.