diff -paur linux-3.5.7/include/linux/sysctl.h linux-3.5.7_sysctls/include/linux/sysctl.h
--- linux-3.5.7/include/linux/sysctl.h	2012-10-12 22:48:25.000000000 +0200
+++ linux-3.5.7_sysctls/include/linux/sysctl.h	2014-10-21 15:14:06.675719641 +0200
@@ -425,6 +425,8 @@ enum
 	NET_TCP_ALLOWED_CONG_CONTROL=123,
 	NET_TCP_MAX_SSTHRESH=124,
 	NET_TCP_FRTO_RESPONSE=125,
+	NET_TCP_DELAYED_ACKS=126,
+	NET_TCP_INITIAL_SSTHRESH=127,
 };
 
 enum {
diff -paur linux-3.5.7/include/net/tcp.h linux-3.5.7_sysctls/include/net/tcp.h
--- linux-3.5.7/include/net/tcp.h	2012-10-12 22:48:25.000000000 +0200
+++ linux-3.5.7_sysctls/include/net/tcp.h	2014-10-21 15:14:42.758720498 +0200
@@ -253,6 +253,9 @@ extern int sysctl_tcp_cookie_size;
 extern int sysctl_tcp_thin_linear_timeouts;
 extern int sysctl_tcp_thin_dupack;
 extern int sysctl_tcp_early_retrans;
+extern int sysctl_tcp_delayed_acks;
+extern int sysctl_tcp_initial_ssthresh;
+
 
 extern atomic_long_t tcp_memory_allocated;
 extern struct percpu_counter tcp_sockets_allocated;
diff -paur linux-3.5.7/kernel/sysctl_binary.c linux-3.5.7_sysctls/kernel/sysctl_binary.c
--- linux-3.5.7/kernel/sysctl_binary.c	2012-10-12 22:48:25.000000000 +0200
+++ linux-3.5.7_sysctls/kernel/sysctl_binary.c	2014-10-21 15:15:18.460721347 +0200
@@ -400,6 +400,8 @@ static const struct bin_table bin_net_ip
 	/* NET_TCP_AVAIL_CONG_CONTROL "tcp_available_congestion_control" no longer used */
 	{ CTL_STR,	NET_TCP_ALLOWED_CONG_CONTROL,		"tcp_allowed_congestion_control" },
 	{ CTL_INT,	NET_TCP_MAX_SSTHRESH,			"tcp_max_ssthresh" },
+	{ CTL_INT,	NET_TCP_DELAYED_ACKS,			"tcp_delayed_acks" },
+	{ CTL_INT,	NET_TCP_INITIAL_SSTHRESH,		"tcp_initial_ssthresh" },
 
 	{ CTL_INT,	NET_IPV4_ICMP_ECHO_IGNORE_ALL,		"icmp_echo_ignore_all" },
 	{ CTL_INT,	NET_IPV4_ICMP_ECHO_IGNORE_BROADCASTS,	"icmp_echo_ignore_broadcasts" },
diff -paur linux-3.5.7/net/ipv4/sysctl_net_ipv4.c linux-3.5.7_sysctls/net/ipv4/sysctl_net_ipv4.c
--- linux-3.5.7/net/ipv4/sysctl_net_ipv4.c	2012-10-12 22:48:25.000000000 +0200
+++ linux-3.5.7_sysctls/net/ipv4/sysctl_net_ipv4.c	2014-10-21 15:16:32.252723100 +0200
@@ -687,6 +687,20 @@ static struct ctl_table ipv4_table[] = {
 		.extra2		= &two,
 	},
 	{
+		.procname	= "tcp_delayed_acks",
+		.data		= &sysctl_tcp_delayed_acks,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+	},
+	{
+		.procname	= "tcp_initial_ssthresh",
+		.data		= &sysctl_tcp_initial_ssthresh,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+	},
+	{
 		.procname	= "udp_mem",
 		.data		= &sysctl_udp_mem,
 		.maxlen		= sizeof(sysctl_udp_mem),
Only in linux-3.5.7_sysctls/net/ipv4: sysctl_net_ipv4.c~
diff -paur linux-3.5.7/net/ipv4/tcp_input.c linux-3.5.7_sysctls/net/ipv4/tcp_input.c
--- linux-3.5.7/net/ipv4/tcp_input.c	2012-10-12 22:48:25.000000000 +0200
+++ linux-3.5.7_sysctls/net/ipv4/tcp_input.c	2014-10-21 15:18:11.793725466 +0200
@@ -101,6 +101,9 @@ int sysctl_tcp_moderate_rcvbuf __read_mo
 int sysctl_tcp_abc __read_mostly;
 int sysctl_tcp_early_retrans __read_mostly = 2;
 
+int sysctl_tcp_delayed_acks __read_mostly = 1;
+int sysctl_tcp_initial_ssthresh __read_mostly = 0;
+
 #define FLAG_DATA		0x01 /* Incoming frame contained data.		*/
 #define FLAG_WIN_UPDATE		0x02 /* Incoming ACK was a window update.	*/
 #define FLAG_DATA_ACKED		0x04 /* This ACK acknowledged new data.		*/
@@ -903,7 +906,10 @@ static void tcp_init_metrics(struct sock
 		/* ssthresh may have been reduced unnecessarily during.
 		 * 3WHS. Restore it back to its initial default.
 		 */
-		tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
+		if (sysctl_tcp_initial_ssthresh > 0)
+		    tp->snd_ssthresh = sysctl_tcp_initial_ssthresh;
+		else
+			tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
 	}
 	if (dst_metric(dst, RTAX_REORDERING) &&
 	    tp->reordering != dst_metric(dst, RTAX_REORDERING)) {
@@ -5219,7 +5225,10 @@ static void __tcp_ack_snd_check(struct s
 		tcp_send_ack(sk);
 	} else {
 		/* Else, send delayed ack. */
-		tcp_send_delayed_ack(sk);
+		if (sysctl_tcp_delayed_acks)
+			tcp_send_delayed_ack(sk);
+		else
+			tcp_send_ack(sk);
 	}
 }