With echo-falure properly set, pptp channel might be disconnected on any fail number (i.e on first fail, never), due failed echo counter contains random value, not actual fail count.
With incoming pptp echo request/l2tp hello there's no need to ask peer for replies in configured echo-interval, assuming the channel is working. So just postpone next request.
It helps against false-positive echo failures with heavily loaded channels and/or peers.
With echo-falure properly set, pptp channel might be disconnected on any fail number (i.e on first fail, never), due failed echo counter contains random value, not actual fail count. With incoming pptp echo request/l2tp hello there's no need to ask peer for replies in configured echo-interval, assuming the channel is working. So just postpone next request. It helps against false-positive echo failures with heavily loaded channels and/or peers.