14  *   o We do not change the loss detection or recovery mechanisms of
18  *     only every-other RTT during slow start, we increase during
21  *     we use the rate at which ACKs come back as the "actual"
23  *   o To speed convergence to the right rate, we set the cwnd
24  *     to achieve the right ("actual") rate when we exit slow start.
25  *   o To filter out the noise caused by delayed ACKs, we use the
54 /* There are several situations when we must "re-start" Vegas:
59  *  o when we send a packet and there is no outstanding
62  * In these circumstances we cannot do a Vegas calculation at the
63  * end of the first RTT, because any calculation we do is using
67  * Instead we must wait until the completion of an RTT during
68  * which we actually receive ACKs.
75 	/* Begin taking Vegas samples next time we send something. */  in vegas_enable()
103  * Basically we:
105  *     propagation delay + queuing delay (we are min-filtering to try to
143  * If the connection is idle and we are restarting,
144  * then we don't want to do any Vegas calculations
145  * until we get fresh RTT samples.  So when we
146  * restart, we reset our Vegas state to a clean
147  * slate. After we get acks for this flight of
148  * packets, _then_ we can make Vegas calculations
177 		/* Save the extent of the current window so we can use this  in tcp_vegas_cong_avoid()
182 		/* We do the Vegas calculations only if we got enough RTT  in tcp_vegas_cong_avoid()
183 		 * samples that we can be reasonably sure that we got  in tcp_vegas_cong_avoid()
185 		 * If we only had 2 samples total,  in tcp_vegas_cong_avoid()
186 		 * then that means we're getting only 1 ACK per RTT, which  in tcp_vegas_cong_avoid()
188 		 * If  we have 3 samples, we should be OK.  in tcp_vegas_cong_avoid()
192 			/* We don't have enough RTT samples to do the Vegas  in tcp_vegas_cong_avoid()
193 			 * calculation, so we'll behave like Reno.  in tcp_vegas_cong_avoid()
200 			/* We have enough RTT samples, so, using the Vegas  in tcp_vegas_cong_avoid()
201 			 * algorithm, we determine if we should increase or  in tcp_vegas_cong_avoid()
205 			/* Pluck out the RTT we are using for the Vegas  in tcp_vegas_cong_avoid()
213 			/* Calculate the cwnd we should have, if we weren't  in tcp_vegas_cong_avoid()
222 			/* Calculate the difference between the window we had,  in tcp_vegas_cong_avoid()
223 			 * and the window we would like to have. This quantity  in tcp_vegas_cong_avoid()
236 				 * Then we add 1 because the integer  in tcp_vegas_cong_avoid()
249 				/* Figure out where we would like cwnd  in tcp_vegas_cong_avoid()
254 					 * we slow down.  in tcp_vegas_cong_avoid()
260 					/* We don't have enough extra packets  in tcp_vegas_cong_avoid()
265 					/* Sending just as fast as we  in tcp_vegas_cong_avoid()