diff -u -wbrP --exclude=config.save linux-2.4.22/net/ipv4/tcp_input.c linux-2.4.22-retrans/net/ipv4/tcp_input.c
--- linux-2.4.22/net/ipv4/tcp_input.c	2003-06-13 15:51:39.000000000 +0100
+++ linux-2.4.22-retrans/net/ipv4/tcp_input.c	2003-10-09 07:59:48.000000000 +0100
@@ -61,6 +61,7 @@
  *		Panu Kuhlberg:		Experimental audit of TCP (re)transmission
  *					engine. Lots of bugs are found.
  *		Pasi Sarolahti:		F-RTO for dealing with spurious RTOs
+ *		Doug Leith:		Early retransmission of packets falling into sack holes.
  */
 
 #include <linux/config.h>
@@ -757,6 +758,10 @@
  *    for retransmitted and already SACKed segment -> reordering..
  * Both of these heuristics are not used in Loss state, when we cannot
  * account for retransmits accurately.
+ *
+ * Retransmission of packets
+ * -------------------------
+ * Extension of Hoe's retransmit to allow early retransmission of packets which fall into sack holes
  */
 static int
 tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_una)
@@ -770,6 +775,7 @@
 	u32 lost_retrans = 0;
 	int flag = 0;
 	int i;
+        u32 prior_sacked_out=tp->sacked_out;
 
 	if (!tp->sacked_out)
 		tp->fackets_out = 0;
@@ -781,6 +787,7 @@
 		__u32 end_seq = ntohl(sp->end_seq);
 		int fack_count = 0;
 		int dup_sack = 0;
+                u32 sack_count=0;
 
 		/* Check for D-SACK. */
 		if (i == 0) {
@@ -828,6 +835,8 @@
 				break;
 
 			fack_count++;
+			if (sacked&TCPCB_RETRANS) 
+			   sack_count++;
 
 			in_sack = !after(start_seq, TCP_SKB_CB(skb)->seq) &&
 				!before(end_seq, TCP_SKB_CB(skb)->end_seq);
@@ -860,8 +869,14 @@
 			    (!lost_retrans || after(end_seq, lost_retrans)))
 				lost_retrans = end_seq;
 
-			if (!in_sack)
+			if (!in_sack) {
+                           /* force early retransmit ? */
+                           if (!(sacked&TCPCB_TAGBITS) && (prior_sacked_out > sack_count + tp->reordering)) {
+                               TCP_SKB_CB(skb)->sacked |= TCPCB_LOST; 
+                               tp->lost_out++;
+                           }
 				continue;
+ 			}
 
 			if (!(sacked&TCPCB_SACKED_ACKED)) {
 				if (sacked & TCPCB_SACKED_RETRANS) {
@@ -1599,7 +1614,7 @@
 	if ((flag&FLAG_DATA_LOST) &&
 	    before(tp->snd_una, tp->high_seq) &&
 	    tp->ca_state != TCP_CA_Open &&
-	    tp->fackets_out > tp->reordering) {
+	    tp->fackets_out > tp->reordering && IsReno(tp) ) {
 		tcp_mark_head_lost(sk, tp, tp->fackets_out-tp->reordering, tp->high_seq);
 		NET_INC_STATS_BH(TCPLoss);
 	}
@@ -1714,7 +1729,7 @@
 		tp->ca_state = TCP_CA_Recovery;
 	}
 
-	if (is_dupack || tcp_head_timedout(sk, tp))
+	if ( (is_dupack || tcp_head_timedout(sk, tp)) && IsReno(tp) )
 		tcp_update_scoreboard(sk, tp);
 	tcp_cwnd_down(tp);
 	tcp_xmit_retransmit_queue(sk);