diff -ruNp linux-2.6.25-rc7/include/net/tcp.h linux-2.6.25-rc7-comments/include/net/tcp.h
--- linux-2.6.25-rc7/include/net/tcp.h	2008-03-27 18:25:07.000000000 -0800
+++ linux-2.6.25-rc7-comments/include/net/tcp.h	2008-04-04 11:05:39.000000000 -0800
@@ -645,7 +645,7 @@ struct tcp_congestion_ops {
 
 	/* return slow start threshold (required) */
 	u32 (*ssthresh)(struct sock *sk);
-	/* lower bound for congestion window (optional) */
+	/* lower bound for congestion window during rate halving (optional) */
 	u32 (*min_cwnd)(const struct sock *sk);
 	/* do new cwnd calculation (required) */
 	void (*cong_avoid)(struct sock *sk, u32 ack, u32 in_flight);
diff -ruNp linux-2.6.25-rc7/net/ipv4/tcp_cong.c linux-2.6.25-rc7-comments/net/ipv4/tcp_cong.c
--- linux-2.6.25-rc7/net/ipv4/tcp_cong.c	2008-03-27 18:25:07.000000000 -0800
+++ linux-2.6.25-rc7-comments/net/ipv4/tcp_cong.c	2008-04-04 11:05:00.000000000 -0800
@@ -387,6 +387,8 @@ u32 tcp_reno_ssthresh(struct sock *sk)
 EXPORT_SYMBOL_GPL(tcp_reno_ssthresh);
 
 /* Lower bound on congestion window with halving. */
+/* Allows snd_cwnd to reduce to prev_cwnd/4  */
+/*   -- see http://oss.sgi.com/archives/netdev/2003-01/msg00114.html */
 u32 tcp_reno_min_cwnd(const struct sock *sk)
 {
 	const struct tcp_sock *tp = tcp_sk(sk);
diff -ruNp linux-2.6.25-rc7/net/ipv4/tcp_input.c linux-2.6.25-rc7-comments/net/ipv4/tcp_input.c
--- linux-2.6.25-rc7/net/ipv4/tcp_input.c	2008-03-27 18:25:07.000000000 -0800
+++ linux-2.6.25-rc7-comments/net/ipv4/tcp_input.c	2008-04-04 11:07:43.000000000 -0800
@@ -2233,14 +2233,15 @@ static inline void tcp_moderate_cwnd(str
 	tp->snd_cwnd_stamp = tcp_time_stamp;
 }
 
-/* Lower bound on congestion window is slow start threshold
+/* Lower bound on congestion window during rate halving is *half* of
+ * slow start threshold (see net/ipv4/tcp_cong.c:tcp_reno_min_cwnd() )
  * unless congestion avoidance choice decides to overide it.
  */
 static inline u32 tcp_cwnd_min(const struct sock *sk)
 {
 	const struct tcp_congestion_ops *ca_ops = inet_csk(sk)->icsk_ca_ops;
 
-	return ca_ops->min_cwnd ? ca_ops->min_cwnd(sk) : tcp_sk(sk)->snd_ssthresh;
+	return ca_ops->min_cwnd ? ca_ops->min_cwnd(sk) : tcp_sk(sk)->snd_ssthresh / 2;
 }
 
 /* Decrease cwnd each second ack. */