resolved

diff --cc send_control.cpp
index 2e04f38,a49909f..75c43c4
--- 1/send_control.cpp
--- 2/send_control.cpp
+++ b/send_control.cpp
@@@ -85,9 -91,10 +91,11 @@@ tint    Channel::PingPongNextSendTime (
  }
  
  tint    Channel::CwndRateNextSendTime () {
+     if (data_in_.bin!=bin64_t::NONE)
+         return NOW; // TODO: delayed ACKs
      send_interval_ = rtt_avg_/cwnd_;
      if (data_out_.size()<cwnd_) {
 +      dprintf("%s #%u sendctrl next in %llius\n",tintstr(),id,send_interval_);
          return last_data_out_time_ + send_interval_;
      } else {
          tint next_timeout = data_out_.front().time + ack_timeout();