I noticed something when letting a relay (non exit) run for a few days: The amount of traffic sent is larger than the amount received.
This is confirmed by looking at the tor log and also by looking at
Examples of one day:
[...]I've sent 556.92 GB and received 456.66 GB.
[...]I've sent 670.04 GB and received 546.71 GB.
[...]I've sent 861.17 GB and received 687.35 GB.
[...]I've sent 1060.14 GB and received 849.68 GB.
Why is that? From my understanding the relay has to forward any traffic it receives from a client or an entry node to the next relay or the exit. Any reply will also flow through the relay the other way around. Shouldn't the amounts of data roughly match?