[tor-relays] excessive bandwidth assigned bandwidth-limited exit relay

[Dhalgren Tor]

Have a new exit running in an excellent network on a very fast server
with AES-NI.  Server plan is limited to100TB so have set a limit
slightly above this (18000000 bytes/sec) thinking that bandwidth would
run 80-90% of the maximum and average to just below the plan limit.
After three days the assigned bandwidth for the relay is going up
instead of moderating--looks like the measurement system has a problem
in this case.  Just dropped the limit to 16500000 to stay below 100TB
with maximum load.

A good number appears to be around 65000 to 70000, but 98000 was just assigned.

What can be done to extract proper rating from measurement system?
Tried setting TokenBucketRefillInterval to 10 milliseconds for more
exact control but this has not helped.  Should an IPTABLES
packet-dropping limit be established?  Can the rating system be fixed?