Index: ipv4/tcp_westwood.c
===================================================================
--- ipv4.orig/tcp_westwood.c	2006-06-06 18:08:03.000000000 +0200
+++ ipv4/tcp_westwood.c	2006-06-06 18:09:44.000000000 +0200
@@ -22,6 +22,7 @@
 	u32    accounted;
 	u32    rtt;
 	u32    rtt_min;          /* minimum observed RTT */
+	u16    first_ack;        /* flag which infers that this is the first ack */
 };
 
 
@@ -52,6 +53,7 @@
 	w->rtt_min = w->rtt = TCP_WESTWOOD_INIT_RTT;
 	w->rtt_win_sx = tcp_time_stamp;
 	w->snd_una = tcp_sk(sk)->snd_una;
+	w->first_ack = 1;
 }
 
 /*
@@ -184,6 +186,15 @@
 {
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct westwood *w = inet_csk_ca(sk);
+	
+	/* Initialise w->snd_una with the first acked sequence number in oder
+	 * to fix mismatch between tp->snd_una and w->snd_una for the first
+	 * bandwidth sample
+	 */
+        if(w->first_ack && (event == CA_EVENT_FAST_ACK||event == CA_EVENT_SLOW_ACK)) {
+		w->snd_una = tp->snd_una;
+		w->first_ack = 0;
+	}
 
 	switch(event) {
 	case CA_EVENT_FAST_ACK: