[j-nsp] inbound policing

[Paul Goyette]

> More than likely it is just the nature of the beast, policers can't be
> perfectly accurate. He might also be able to get more exact performance by
> tuning the burst limit, though "to what" is something I'm not even going
> to try and touch. Why Juniper hasn't added an "auto-burst-limit" directive
> or some kind of bandwidth/delay calculator with recommended values to the
> CLI is still beyond me. :P

Maybe for the exact same reason that you won't "try and touch it"?  :)