diff --git a/sys/netinet/tcp_input.c b/sys/netinet/tcp_input.c
index c3b562f61793..cbd40689732c 100644
--- a/sys/netinet/tcp_input.c
+++ b/sys/netinet/tcp_input.c
@@ -1840,9 +1840,8 @@ trimthenstep6:
 				else if (++tp->t_dupacks > tcprexmtthresh ||
 					 ((tcp_do_newreno || tp->sack_enable) &&
 					  IN_FASTRECOVERY(tp))) {
-
                                         if (tp->sack_enable && IN_FASTRECOVERY(tp)) {
-						int data_in_pipe;
+						int awnd;
 						
 						/*
 						 * Compute the amount of data in flight first.
@@ -1850,9 +1849,9 @@ trimthenstep6:
 						 * we have less than 1/2 the original window's 	
 						 * worth of data in flight.
 						 */
-						data_in_pipe = (tp->snd_nxt - tp->rcv_lastsack) +
+						awnd = (tp->snd_nxt - tp->snd_fack) +
 							tp->sackhint.sack_bytes_rexmit;
-						if (data_in_pipe < tp->snd_ssthresh) {
+						if (awnd < tp->snd_ssthresh) {
 							tp->snd_cwnd += tp->t_maxseg;
 							if (tp->snd_cwnd > tp->snd_ssthresh)
 								tp->snd_cwnd = tp->snd_ssthresh;
diff --git a/sys/netinet/tcp_reass.c b/sys/netinet/tcp_reass.c
index c3b562f61793..cbd40689732c 100644
--- a/sys/netinet/tcp_reass.c
+++ b/sys/netinet/tcp_reass.c
@@ -1840,9 +1840,8 @@ trimthenstep6:
 				else if (++tp->t_dupacks > tcprexmtthresh ||
 					 ((tcp_do_newreno || tp->sack_enable) &&
 					  IN_FASTRECOVERY(tp))) {
-
                                         if (tp->sack_enable && IN_FASTRECOVERY(tp)) {
-						int data_in_pipe;
+						int awnd;
 						
 						/*
 						 * Compute the amount of data in flight first.
@@ -1850,9 +1849,9 @@ trimthenstep6:
 						 * we have less than 1/2 the original window's 	
 						 * worth of data in flight.
 						 */
-						data_in_pipe = (tp->snd_nxt - tp->rcv_lastsack) +
+						awnd = (tp->snd_nxt - tp->snd_fack) +
 							tp->sackhint.sack_bytes_rexmit;
-						if (data_in_pipe < tp->snd_ssthresh) {
+						if (awnd < tp->snd_ssthresh) {
 							tp->snd_cwnd += tp->t_maxseg;
 							if (tp->snd_cwnd > tp->snd_ssthresh)
 								tp->snd_cwnd = tp->snd_ssthresh;
diff --git a/sys/netinet/tcp_sack.c b/sys/netinet/tcp_sack.c
index a970c19883fe..5ff7c34abc4b 100644
--- a/sys/netinet/tcp_sack.c
+++ b/sys/netinet/tcp_sack.c
@@ -389,12 +389,12 @@ tcp_sack_option(struct tcpcb *tp, struct tcphdr *th, u_char *cp, int optlen)
 	}
 	if (TAILQ_EMPTY(&tp->snd_holes))
 		/*
-		 * Empty scoreboard. Need to initialize rcv_lastsack (it may be
+		 * Empty scoreboard. Need to initialize snd_fack (it may be
 		 * uninitialized or have a bogus value). Scoreboard holes
 		 * (from the sack blocks received) are created later below (in
 		 * the logic that adds holes to the tail of the scoreboard).
 		 */
-		tp->rcv_lastsack = tp->snd_una;
+		tp->snd_fack = tp->snd_una;
 	next_sack_blk = 0;
 	cur = TAILQ_FIRST(&tp->snd_holes);
 	/*
@@ -403,7 +403,7 @@ tcp_sack_option(struct tcpcb *tp, struct tcphdr *th, u_char *cp, int optlen)
 	 */
 	while ((next_sack_blk < num_sack_blks) && (cur != NULL)) {
 		sack = sack_blocks[next_sack_blk];
-		if (SEQ_LT(tp->rcv_lastsack, sack.start))
+		if (SEQ_LT(tp->snd_fack, sack.start))
 			/*
 			 * The sack block acks data to the right of all the holes
 			 * in the scoreboard. No need to iterate over the
@@ -495,19 +495,19 @@ tcp_sack_option(struct tcpcb *tp, struct tcphdr *th, u_char *cp, int optlen)
 		 * sack.start and sack.end seem redundant, but they're necessary
 		 * to deal with overlapping sack blocks.
 		 */
-		if (SEQ_LT(tp->rcv_lastsack, sack.start)) {
+		if (SEQ_LT(tp->snd_fack, sack.start)) {
 			/* Need to append new hole at end. */
-			temp = tcp_sackhole_alloc(tp, tp->rcv_lastsack,
+			temp = tcp_sackhole_alloc(tp, tp->snd_fack,
 						  sack.start);
 			if (temp == NULL)
 				continue; /* ENOBUFS */
 			TAILQ_INSERT_TAIL(&tp->snd_holes, temp, scblink);
-			tp->rcv_lastsack = sack.end;
+			tp->snd_fack = sack.end;
 			if (tp->sackhint.nexthole == NULL)
 				tp->sackhint.nexthole = temp;
 		}
-		if (SEQ_LT(tp->rcv_lastsack, sack.end))
-			tp->rcv_lastsack = sack.end;
+		if (SEQ_LT(tp->snd_fack, sack.end))
+			tp->snd_fack = sack.end;
 	}
 	return (0);
 }
@@ -689,12 +689,12 @@ tcp_sack_adjust(struct tcpcb *tp)
 	INP_LOCK_ASSERT(tp->t_inpcb);
 	if (cur == NULL)
 		return; /* No holes */
-	if (SEQ_GEQ(tp->snd_nxt, tp->rcv_lastsack))
+	if (SEQ_GEQ(tp->snd_nxt, tp->snd_fack))
 		return; /* We're already beyond any SACKed blocks */
 	/*
 	 * Two cases for which we want to advance snd_nxt:
 	 * i) snd_nxt lies between end of one hole and beginning of another
-	 * ii) snd_nxt lies between end of last hole and rcv_lastsack
+	 * ii) snd_nxt lies between end of last hole and snd_fack
 	 */
 	while ((p = TAILQ_NEXT(cur, scblink)) != NULL) {
 		if (SEQ_LT(tp->snd_nxt, cur->end))
@@ -708,6 +708,6 @@ tcp_sack_adjust(struct tcpcb *tp)
 	}
 	if (SEQ_LT(tp->snd_nxt, cur->end))
 		return;
-	tp->snd_nxt = tp->rcv_lastsack;
+	tp->snd_nxt = tp->snd_fack;
 	return;
 }
diff --git a/sys/netinet/tcp_var.h b/sys/netinet/tcp_var.h
index 0d777ee7a94b..108c1a6684ac 100644
--- a/sys/netinet/tcp_var.h
+++ b/sys/netinet/tcp_var.h
@@ -192,7 +192,7 @@ struct tcpcb {
 	int	sack_enable;		/* enable SACK for this connection */
 	int	snd_numholes;		/* number of holes seen by sender */
 	TAILQ_HEAD(, sackhole) snd_holes;	/* SACK scoreboard (sorted) */
-	tcp_seq	rcv_lastsack;		/* last seq number(+1) sack'd by rcv'r*/
+	tcp_seq	snd_fack;		/* last seq number(+1) sack'd by rcv'r*/
 	int	rcv_numsacks;		/* # distinct sack blks present */
 	struct sackblk sackblks[MAX_SACK_BLKS]; /* seq nos. of sack blocks */
 	tcp_seq sack_newdata;		/* New data xmitted in this recovery