diff --git a/buffer.c b/buffer.c
index d240f67..88e16d0 100644
--- a/buffer.c
+++ b/buffer.c
@@ -128,7 +128,7 @@ restart:
 
 	/* Increase the size of the buffer and retry. */
 	newlen = roundup(buffer->alloc + len, BUFFER_ALLOCSZ);
-	if (newlen > BUFFER_MAX_LEN)
+	if (newlen > BUFFER_MAX_LEN_HPN)
 		fatal("buffer_append_space: alloc %u not supported",
 		    newlen);
 	buffer->buf = xrealloc(buffer->buf, 1, newlen);
diff --git a/buffer.h b/buffer.h
index 7df8a38..244de01 100644
--- a/buffer.h
+++ b/buffer.h
@@ -16,6 +16,9 @@
 #ifndef BUFFER_H
 #define BUFFER_H
 
+/* move the following to a more appropriate place and name */
+#define BUFFER_MAX_LEN_HPN          0x4000000  /* 64MB */
+
 typedef struct {
 	u_char	*buf;		/* Buffer for data. */
 	u_int	 alloc;		/* Number of bytes allocated for data. */
diff --git a/channels.c b/channels.c
index 9efe89c..bb01516 100644
--- a/channels.c
+++ b/channels.c
@@ -173,8 +173,14 @@ static void port_open_helper(Channel *c, char *rtype);
 static int connect_next(struct channel_connect *);
 static void channel_connect_ctx_free(struct channel_connect *);
 
+
+static int hpn_disabled = 0;
+static int hpn_buffer_size = 2 * 1024 * 1024;
+
 /* -- channel core */
 
+
+
 Channel *
 channel_by_id(int id)
 {
@@ -323,6 +329,7 @@ channel_new(char *ctype, int type, int rfd, int wfd, int efd,
 	c->local_window_max = window;
 	c->local_consumed = 0;
 	c->local_maxpacket = maxpack;
+	c->dynamic_window = 0;
 	c->remote_id = -1;
 	c->remote_name = xstrdup(remote_name);
 	c->remote_window = 0;
@@ -819,11 +826,35 @@ channel_pre_open_13(Channel *c, fd_set *readset, fd_set *writeset)
 		FD_SET(c->sock, writeset);
 }
 
+int channel_tcpwinsz () {
+        u_int32_t tcpwinsz = 0;
+        socklen_t optsz = sizeof(tcpwinsz);
+	int ret = -1;
+
+	/* if we aren't on a socket return 128KB*/
+	if(!packet_connection_is_on_socket())
+	    return(128*1024);
+	ret = getsockopt(packet_get_connection_in(),
+			 SOL_SOCKET, SO_RCVBUF, &tcpwinsz, &optsz);
+	/* return no more than 64MB */
+	if ((ret == 0) && tcpwinsz > BUFFER_MAX_LEN_HPN)
+	    tcpwinsz = BUFFER_MAX_LEN_HPN;
+	debug2("tcpwinsz: %d for connection: %d", tcpwinsz,
+	       packet_get_connection_in());
+	return(tcpwinsz);
+}
+
 static void
 channel_pre_open(Channel *c, fd_set *readset, fd_set *writeset)
 {
 	u_int limit = compat20 ? c->remote_window : packet_get_maxsize();
 
+	/* check buffer limits */
+	if ((!c->tcpwinsz) || (c->dynamic_window > 0))
+		c->tcpwinsz = channel_tcpwinsz();
+
+	limit = MIN(limit, 2 * c->tcpwinsz);
+
 	if (c->istate == CHAN_INPUT_OPEN &&
 	    limit > 0 &&
 	    buffer_len(&c->input) < limit &&
@@ -1815,14 +1846,21 @@ channel_check_window(Channel *c)
 	    c->local_maxpacket*3) ||
 	    c->local_window < c->local_window_max/2) &&
 	    c->local_consumed > 0) {
+		u_int addition = 0;
+		/* adjust max window size if we are in a dynamic environment */
+		if (c->dynamic_window && (c->tcpwinsz > c->local_window_max)) {
+			/* grow the window somewhat aggressively to maintain pressure */
+			addition = 1.5*(c->tcpwinsz - c->local_window_max);
+			c->local_window_max += addition;
+		}
 		packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
 		packet_put_int(c->remote_id);
-		packet_put_int(c->local_consumed);
+		packet_put_int(c->local_consumed + addition);
 		packet_send();
 		debug2("channel %d: window %d sent adjust %d",
 		    c->self, c->local_window,
 		    c->local_consumed);
-		c->local_window += c->local_consumed;
+		c->local_window += c->local_consumed + addition;
 		c->local_consumed = 0;
 	}
 	return 1;
@@ -2738,6 +2776,15 @@ channel_fwd_bind_addr(const char *listen_addr, int *wildcardp,
 	return addr;
 }
 
+
+void
+channel_set_hpn(int external_hpn_disabled, int external_hpn_buffer_size)
+{
+	hpn_disabled = external_hpn_disabled;
+	hpn_buffer_size = external_hpn_buffer_size;
+	debug("HPN Disabled: %d, HPN Buffer Size: %d", hpn_disabled, hpn_buffer_size);
+}
+
 static int
 channel_setup_fwd_listener(int type, const char *listen_addr,
     u_short listen_port, int *allocated_listen_port,
@@ -2864,9 +2911,15 @@ channel_setup_fwd_listener(int type, const char *listen_addr,
 		}
 
 		/* Allocate a channel number for the socket. */
+		/* explicitly test for hpn disabled option. if true use smaller window size */
+		if (hpn_disabled)
 		c = channel_new("port listener", type, sock, sock, -1,
 		    CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
 		    0, "port listener", 1);
+ 		else
+ 			c = channel_new("port listener", type, sock, sock, -1,
+ 			  hpn_buffer_size, CHAN_TCP_PACKET_DEFAULT,
+ 			  0, "port listener", 1);
 		c->path = xstrdup(host);
 		c->host_port = port_to_connect;
 		c->listening_addr = addr == NULL ? NULL : xstrdup(addr);
@@ -3514,10 +3567,17 @@ x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
 	*chanids = xcalloc(num_socks + 1, sizeof(**chanids));
 	for (n = 0; n < num_socks; n++) {
 		sock = socks[n];
+		/* Is this really necassary? */
+		if (hpn_disabled)
 		nc = channel_new("x11 listener",
 		    SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
 		    CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
 		    0, "X11 inet listener", 1);
+		else
+			nc = channel_new("x11 listener",
+			    SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
+			    hpn_buffer_size, CHAN_X11_PACKET_DEFAULT,
+			    0, "X11 inet listener", 1);
 		nc->single_connection = single_connection;
 		(*chanids)[n] = nc->self;
 	}
diff --git a/channels.h b/channels.h
index 4fab9d7..91ef316 100644
--- a/channels.h
+++ b/channels.h
@@ -132,8 +132,10 @@ struct Channel {
 	u_int	local_window_max;
 	u_int	local_consumed;
 	u_int	local_maxpacket;
+	int	dynamic_window;
 	int     extended_usage;
 	int	single_connection;
+	u_int	tcpwinsz;
 
 	char   *ctype;		/* type */
 
@@ -169,8 +171,10 @@ struct Channel {
 /* default window/packet sizes for tcp/x11-fwd-channel */
 #define CHAN_SES_PACKET_DEFAULT	(32*1024)
 #define CHAN_SES_WINDOW_DEFAULT	(64*CHAN_SES_PACKET_DEFAULT)
+
 #define CHAN_TCP_PACKET_DEFAULT	(32*1024)
 #define CHAN_TCP_WINDOW_DEFAULT	(64*CHAN_TCP_PACKET_DEFAULT)
+
 #define CHAN_X11_PACKET_DEFAULT	(16*1024)
 #define CHAN_X11_WINDOW_DEFAULT	(4*CHAN_X11_PACKET_DEFAULT)
 
@@ -306,4 +310,7 @@ void	 chan_rcvd_ieof(Channel *);
 void	 chan_write_failed(Channel *);
 void	 chan_obuf_empty(Channel *);
 
+/* hpn handler */
+void     channel_set_hpn(int, int);
+
 #endif
diff --git a/cipher.c b/cipher.c
index 53d9b4f..74ba34e 100644
--- a/cipher.c
+++ b/cipher.c
@@ -71,7 +71,7 @@ struct Cipher {
 	const EVP_CIPHER	*(*evptype)(void);
 };
 
-static const struct Cipher ciphers[] = {
+static struct Cipher ciphers[] = {
 	{ "none",	SSH_CIPHER_NONE, 8, 0, 0, 0, 0, 0, EVP_enc_null },
 	{ "des",	SSH_CIPHER_DES, 8, 8, 0, 0, 0, 1, EVP_des_cbc },
 	{ "3des",	SSH_CIPHER_3DES, 8, 16, 0, 0, 0, 1, evp_ssh1_3des },
@@ -193,7 +193,7 @@ cipher_mask_ssh1(int client)
 const Cipher *
 cipher_by_name(const char *name)
 {
-	const Cipher *c;
+	Cipher *c;
 	for (c = ciphers; c->name != NULL; c++)
 		if (strcmp(c->name, name) == 0)
 			return c;
diff --git a/clientloop.c b/clientloop.c
index 59ad3a2..e144fb6 100644
--- a/clientloop.c
+++ b/clientloop.c
@@ -1891,9 +1891,15 @@ client_request_x11(const char *request_type, int rchan)
 	sock = x11_connect_display();
 	if (sock < 0)
 		return NULL;
+	/* again is this really necessary for X11? */
+	if (options.hpn_disabled)
 	c = channel_new("x11",
 	    SSH_CHANNEL_X11_OPEN, sock, sock, -1,
 	    CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1);
+	else
+		c = channel_new("x11",
+		    SSH_CHANNEL_X11_OPEN, sock, sock, -1,
+		    options.hpn_buffer_size, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1);
 	c->force_drain = 1;
 	return c;
 }
@@ -1913,9 +1919,15 @@ client_request_agent(const char *request_type, int rchan)
 	sock = ssh_get_authentication_socket();
 	if (sock < 0)
 		return NULL;
+	if (options.hpn_disabled)
+	c = channel_new("authentication agent connection",
+	    SSH_CHANNEL_OPEN, sock, sock, -1,
+		    CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
+		    "authentication agent connection", 1);
+	else
 	c = channel_new("authentication agent connection",
 	    SSH_CHANNEL_OPEN, sock, sock, -1,
-	    CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0,
+	    options.hpn_buffer_size, options.hpn_buffer_size, 0,
 	    "authentication agent connection", 1);
 	c->force_drain = 1;
 	return c;
@@ -1943,10 +1955,18 @@ client_request_tun_fwd(int tun_mode, int local_tun, int remote_tun)
 		return -1;
 	}
 
+	if(options.hpn_disabled)
 	c = channel_new("tun", SSH_CHANNEL_OPENING, fd, fd, -1,
-	    CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1);
+				CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
+				0, "tun", 1);
+	else
+	c = channel_new("tun", SSH_CHANNEL_OPENING, fd, fd, -1,
+				options.hpn_buffer_size, CHAN_TCP_PACKET_DEFAULT,
+				0, "tun", 1);
 	c->datagram = 1;
 
+
+
 #if defined(SSH_TUN_FILTER)
 	if (options.tun_open == SSH_TUNMODE_POINTOPOINT)
 		channel_register_filter(c->self, sys_tun_infilter,
diff --git a/compat.c b/compat.c
index 9d9fabe..235fc59 100644
--- a/compat.c
+++ b/compat.c
@@ -172,6 +172,15 @@ compat_datafellows(const char *version)
 		if (match_pattern_list(version, check[i].pat,
 		    strlen(check[i].pat), 0) == 1) {
 			datafellows = check[i].bugs;
+			/* Check to see if the remote side is OpenSSH and not HPN */
+			if(strstr(version,"OpenSSH") != NULL)
+			{
+				if (strstr(version,"hpn") == NULL)
+				{
+					datafellows |= SSH_BUG_LARGEWINDOW;
+					debug("Remote is NON-HPN aware");
+				}
+			}
 			debug("match: %s pat %s compat 0x%08x",
 			    version, check[i].pat, datafellows);
 			return;
diff --git a/compat.h b/compat.h
index b174fa1..9937347 100644
--- a/compat.h
+++ b/compat.h
@@ -59,6 +59,7 @@
 #define SSH_BUG_RFWD_ADDR	0x02000000
 #define SSH_NEW_OPENSSH		0x04000000
 #define SSH_BUG_DYNAMIC_RPORT	0x08000000
+#define SSH_BUG_LARGEWINDOW     0x10000000
 
 void     enable_compat13(void);
 void     enable_compat20(void);
diff --git a/readconf.c b/readconf.c
index dc884c9..ce083f4 100644
--- a/readconf.c
+++ b/readconf.c
@@ -149,6 +149,7 @@ typedef enum {
 	oKexAlgorithms, oIPQoS, oRequestTTY, oIgnoreUnknown, oProxyUseFdpass,
 	oCanonicalDomains, oCanonicalizeHostname, oCanonicalizeMaxDots,
 	oCanonicalizeFallbackLocal, oCanonicalizePermittedCNAMEs,
+	oTcpRcvBufPoll, oTcpRcvBuf, oHPNDisabled, oHPNBufferSize,
 	oIgnoredUnknownOption, oDeprecated, oUnsupported
 } OpCodes;
 
@@ -263,6 +264,11 @@ static struct {
 	{ "canonicalizepermittedcnames", oCanonicalizePermittedCNAMEs },
 	{ "ignoreunknown", oIgnoreUnknown },
 
+	{ "tcprcvbufpoll", oTcpRcvBufPoll },
+	{ "tcprcvbuf", oTcpRcvBuf },
+	{ "hpndisabled", oHPNDisabled },
+	{ "hpnbuffersize", oHPNBufferSize },
+
 	{ NULL, oBadOption }
 };
 
@@ -853,6 +859,18 @@ parse_time:
 		intptr = &options->check_host_ip;
 		goto parse_flag;
 
+	case oHPNDisabled:
+		intptr = &options->hpn_disabled;
+		goto parse_flag;
+
+	case oHPNBufferSize:
+		intptr = &options->hpn_buffer_size;
+		goto parse_int;
+
+	case oTcpRcvBufPoll:
+		intptr = &options->tcp_rcv_buf_poll;
+		goto parse_flag;
+
 	case oVerifyHostKeyDNS:
 		intptr = &options->verify_host_key_dns;
 		multistate_ptr = multistate_yesnoask;
@@ -1015,6 +1033,10 @@ parse_int:
 		intptr = &options->connection_attempts;
 		goto parse_int;
 
+	case oTcpRcvBuf:
+		intptr = &options->tcp_rcv_buf;
+		goto parse_int;
+
 	case oCipher:
 		intptr = &options->cipher;
 		arg = strdelim(&s);
@@ -1561,6 +1583,10 @@ initialize_options(Options * options)
 	options->ip_qos_interactive = -1;
 	options->ip_qos_bulk = -1;
 	options->request_tty = -1;
+	options->hpn_disabled = -1;
+	options->hpn_buffer_size = -1;
+	options->tcp_rcv_buf_poll = -1;
+	options->tcp_rcv_buf = -1;
 	options->proxy_use_fdpass = -1;
 	options->ignored_unknown = NULL;
 	options->num_canonical_domains = 0;
@@ -1707,6 +1733,28 @@ fill_default_options(Options * options)
 		options->server_alive_interval = 0;
 	if (options->server_alive_count_max == -1)
 		options->server_alive_count_max = 3;
+	if (options->hpn_disabled == -1)
+	        options->hpn_disabled = 0;
+	if (options->hpn_buffer_size > -1)
+	{
+	  /* if a user tries to set the size to 0 set it to 1KB */
+		if (options->hpn_buffer_size == 0)
+		options->hpn_buffer_size = 1;
+		/*limit the buffer to 64MB*/
+		if (options->hpn_buffer_size > 64*1024)
+		{
+			options->hpn_buffer_size = 64*1024*1024;
+			debug("User requested buffer larger than 64MB. Request reverted to 64MB");
+		}
+		else options->hpn_buffer_size *= 1024;
+		debug("hpn_buffer_size set to %d", options->hpn_buffer_size);
+	}
+	if (options->tcp_rcv_buf == 0)
+		options->tcp_rcv_buf = 1;
+	if (options->tcp_rcv_buf > -1)
+		options->tcp_rcv_buf *=1024;
+	if (options->tcp_rcv_buf_poll == -1)
+		options->tcp_rcv_buf_poll = 1;
 	if (options->control_master == -1)
 		options->control_master = 0;
 	if (options->control_persist == -1) {
diff --git a/readconf.h b/readconf.h
index 75e3f8f..a471114 100644
--- a/readconf.h
+++ b/readconf.h
@@ -66,6 +66,10 @@ typedef struct {
 	int     compression_level;	/* Compression level 1 (fast) to 9
 					 * (best). */
 	int     tcp_keep_alive;	/* Set SO_KEEPALIVE. */
+	int     tcp_rcv_buf; /* user switch to set tcp recv buffer */
+	int     tcp_rcv_buf_poll; /* Option to poll recv buf every window transfer */
+	int     hpn_disabled;    /* Switch to disable HPN buffer management */
+	int     hpn_buffer_size; /* User definable size for HPN buffer window */
 	int	ip_qos_interactive;	/* IP ToS/DSCP/class for interactive */
 	int	ip_qos_bulk;		/* IP ToS/DSCP/class for bulk traffic */
 	LogLevel log_level;	/* Level for logging. */
diff --git a/scp.c b/scp.c
index 18d3b1d..2ab8f15 100644
--- a/scp.c
+++ b/scp.c
@@ -749,7 +749,7 @@ source(int argc, char **argv)
 	off_t i, statbytes;
 	size_t amt;
 	int fd = -1, haderr, indx;
-	char *last, *name, buf[2048], encname[MAXPATHLEN];
+	char *last, *name, buf[16384], encname[MAXPATHLEN];
 	int len;
 
 	for (indx = 0; indx < argc; ++indx) {
@@ -914,7 +914,7 @@ sink(int argc, char **argv)
 	off_t size, statbytes;
 	unsigned long long ull;
 	int setimes, targisdir, wrerrno = 0;
-	char ch, *cp, *np, *targ, *why, *vect[1], buf[2048];
+	char ch, *cp, *np, *targ, *why, *vect[1], buf[16384];
 	struct timeval tv[2];
 
 #define	atime	tv[0]
diff --git a/servconf.c b/servconf.c
index 7ba65d5..32bb711 100644
--- a/servconf.c
+++ b/servconf.c
@@ -150,6 +150,9 @@ initialize_server_options(ServerOptions *options)
 	options->revoked_keys_file = NULL;
 	options->trusted_user_ca_keys = NULL;
 	options->authorized_principals_file = NULL;
+	options->tcp_rcv_buf_poll = -1;
+	options->hpn_disabled = -1;
+	options->hpn_buffer_size = -1;
 	options->ip_qos_interactive = -1;
 	options->ip_qos_bulk = -1;
 	options->version_addendum = NULL;
@@ -158,6 +161,11 @@ initialize_server_options(ServerOptions *options)
 void
 fill_default_server_options(ServerOptions *options)
 {
+	/* needed for hpn socket tests */
+	int sock;
+	int socksize;
+	int socksizelen = sizeof(int);
+
 	/* Portable-specific options */
 	if (options->use_pam == -1)
 		options->use_pam = 0;
@@ -294,6 +302,41 @@ fill_default_server_options(ServerOptions *options)
 	}
 	if (options->permit_tun == -1)
 		options->permit_tun = SSH_TUNMODE_NO;
+       if (options->hpn_disabled == -1)
+               options->hpn_disabled = 0;
+
+       if (options->hpn_buffer_size == -1) {
+		/* option not explicitly set. Now we have to figure out */
+		/* what value to use */
+		if (options->hpn_disabled == 1) {
+			options->hpn_buffer_size = CHAN_SES_WINDOW_DEFAULT;
+		} else {
+			/* get the current RCV size and set it to that */
+			/*create a socket but don't connect it */
+			/* we use that the get the rcv socket size */
+			sock = socket(AF_INET, SOCK_STREAM, 0);
+			getsockopt(sock, SOL_SOCKET, SO_RCVBUF,
+				   &socksize, &socksizelen);
+			close(sock);
+			options->hpn_buffer_size = socksize;
+			debug ("HPN Buffer Size: %d", options->hpn_buffer_size);
+		}
+	} else {
+		/* we have to do this incase the user sets both values in a contradictory */
+		/* manner. hpn_disabled overrrides hpn_buffer_size*/
+		if (options->hpn_disabled <= 0) {
+			if (options->hpn_buffer_size == 0)
+				options->hpn_buffer_size = 1;
+			/* limit the maximum buffer to 64MB */
+			if (options->hpn_buffer_size > 64*1024) {
+				options->hpn_buffer_size = 64*1024*1024;
+			} else {
+				options->hpn_buffer_size *= 1024;
+			}
+		} else
+			options->hpn_buffer_size = CHAN_TCP_WINDOW_DEFAULT;
+	}
+
 	if (options->ip_qos_interactive == -1)
 		options->ip_qos_interactive = IPTOS_LOWDELAY;
 	if (options->ip_qos_bulk == -1)
@@ -345,6 +388,7 @@ typedef enum {
 	sUsePrivilegeSeparation, sAllowAgentForwarding,
 	sHostCertificate,
 	sRevokedKeys, sTrustedUserCAKeys, sAuthorizedPrincipalsFile,
+	sTcpRcvBufPoll, sHPNDisabled, sHPNBufferSize,
 	sKexAlgorithms, sIPQoS, sVersionAddendum,
 	sAuthorizedKeysCommand, sAuthorizedKeysCommandUser,
 	sAuthenticationMethods, sHostKeyAgent,
@@ -468,6 +512,9 @@ static struct {
 	{ "revokedkeys", sRevokedKeys, SSHCFG_ALL },
 	{ "trustedusercakeys", sTrustedUserCAKeys, SSHCFG_ALL },
 	{ "authorizedprincipalsfile", sAuthorizedPrincipalsFile, SSHCFG_ALL },
+	{ "hpndisabled", sHPNDisabled, SSHCFG_ALL },
+	{ "hpnbuffersize", sHPNBufferSize, SSHCFG_ALL },
+	{ "tcprcvbufpoll", sTcpRcvBufPoll, SSHCFG_ALL },
 	{ "kexalgorithms", sKexAlgorithms, SSHCFG_GLOBAL },
 	{ "ipqos", sIPQoS, SSHCFG_ALL },
 	{ "authorizedkeyscommand", sAuthorizedKeysCommand, SSHCFG_ALL },
@@ -500,6 +547,7 @@ parse_token(const char *cp, const char *filename,
 
 	for (i = 0; keywords[i].name; i++)
 		if (strcasecmp(cp, keywords[i].name) == 0) {
+			debug ("Config token is %s", keywords[i].name);
 			*flags = keywords[i].flags;
 			return keywords[i].opcode;
 		}
@@ -1042,6 +1090,19 @@ process_server_config_line(ServerOptions *options, char *line,
 			*intptr = value;
 		break;
 
+
+	case sTcpRcvBufPoll:
+		intptr = &options->tcp_rcv_buf_poll;
+		goto parse_flag;
+
+	case sHPNDisabled:
+		intptr = &options->hpn_disabled;
+		goto parse_flag;
+
+	case sHPNBufferSize:
+		intptr = &options->hpn_buffer_size;
+		goto parse_int;
+
 	case sIgnoreUserKnownHosts:
 		intptr = &options->ignore_user_known_hosts;
 		goto parse_flag;
diff --git a/servconf.h b/servconf.h
index 752d1c5..0b9f59d 100644
--- a/servconf.h
+++ b/servconf.h
@@ -164,6 +164,9 @@ typedef struct {
 	char   *adm_forced_command;
 
 	int	use_pam;		/* Enable auth via PAM */
+        int     tcp_rcv_buf_poll;       /* poll tcp rcv window in autotuning kernels*/
+	int	hpn_disabled;		/* disable hpn functionality. false by default */
+	int	hpn_buffer_size;	/* set the hpn buffer size - default 3MB */
 
 	int	permit_tun;
 
diff --git a/serverloop.c b/serverloop.c
index 2f8e3a0..4868e5f 100644
--- a/serverloop.c
+++ b/serverloop.c
@@ -1015,8 +1015,12 @@ server_request_tun(void)
 	sock = tun_open(tun, mode);
 	if (sock < 0)
 		goto done;
+	if (options.hpn_disabled)
 	c = channel_new("tun", SSH_CHANNEL_OPEN, sock, sock, -1,
 	    CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1);
+	else
+		c = channel_new("tun", SSH_CHANNEL_OPEN, sock, sock, -1,
+		    options.hpn_buffer_size, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1);
 	c->datagram = 1;
 #if defined(SSH_TUN_FILTER)
 	if (mode == SSH_TUNMODE_POINTOPOINT)
@@ -1052,6 +1056,8 @@ server_request_session(void)
 	c = channel_new("session", SSH_CHANNEL_LARVAL,
 	    -1, -1, -1, /*window size*/0, CHAN_SES_PACKET_DEFAULT,
 	    0, "server-session", 1);
+	if ((options.tcp_rcv_buf_poll) && (!options.hpn_disabled))
+		c->dynamic_window = 1;
 	if (session_open(the_authctxt, c->self) != 1) {
 		debug("session open failed, free channel %d", c->self);
 		channel_free(c);
diff --git a/session.c b/session.c
index 2bcf818..817afc9 100644
--- a/session.c
+++ b/session.c
@@ -237,6 +237,7 @@ auth_input_request_forwarding(struct passwd * pw)
 	}
 
 	/* Allocate a channel for the authentication agent socket. */
+	/* this shouldn't matter if its hpn or not - cjr */
 	nc = channel_new("auth socket",
 	    SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
 	    CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
@@ -2331,10 +2332,16 @@ session_set_fds(Session *s, int fdin, int fdout, int fderr, int ignore_fderr,
 	 */
 	if (s->chanid == -1)
 		fatal("no channel for session %d", s->self);
+	if (options.hpn_disabled)
 	channel_set_fds(s->chanid,
 	    fdout, fdin, fderr,
 	    ignore_fderr ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
 	    1, is_tty, CHAN_SES_WINDOW_DEFAULT);
+	else
+		channel_set_fds(s->chanid,
+		    fdout, fdin, fderr,
+		    ignore_fderr ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
+		    1, is_tty, options.hpn_buffer_size);
 }
 
 /*
diff --git a/sftp.1 b/sftp.1
index a700c2a..8e00b13 100644
--- a/sftp.1
+++ b/sftp.1
@@ -261,7 +261,8 @@ diagnostic messages from
 Specify how many requests may be outstanding at any one time.
 Increasing this may slightly improve file transfer speed
 but will increase memory usage.
-The default is 64 outstanding requests.
+The default is 256 outstanding requests providing for 8MB
+of outstanding data with a 32KB buffer.
 .It Fl r
 Recursively copy entire directories when uploading and downloading.
 Note that
diff --git a/sftp.c b/sftp.c
index ad1f8c8..1575d5e 100644
--- a/sftp.c
+++ b/sftp.c
@@ -68,7 +68,7 @@ typedef void EditLine;
 #include "sftp-client.h"
 
 #define DEFAULT_COPY_BUFLEN	32768	/* Size of buffer for up/download */
-#define DEFAULT_NUM_REQUESTS	64	/* # concurrent outstanding requests */
+#define DEFAULT_NUM_REQUESTS	256	/* # concurrent outstanding requests */
 
 /* File to read commands from */
 FILE* infile;
diff --git a/ssh.c b/ssh.c
index 1e6cb90..7c91d6d 100644
--- a/ssh.c
+++ b/ssh.c
@@ -1611,6 +1611,9 @@ ssh_session2_open(void)
 {
 	Channel *c;
 	int window, packetmax, in, out, err;
+	int sock;
+	int socksize;
+	int socksizelen = sizeof(int);
 
 	if (stdin_null_flag) {
 		in = open(_PATH_DEVNULL, O_RDONLY);
@@ -1631,9 +1634,74 @@ ssh_session2_open(void)
 	if (!isatty(err))
 		set_nonblock(err);
 
-	window = CHAN_SES_WINDOW_DEFAULT;
+	/* we need to check to see if what they want to do about buffer */
+	/* sizes here. In a hpn to nonhpn connection we want to limit */
+	/* the window size to something reasonable in case the far side */
+	/* has the large window bug. In hpn to hpn connection we want to */
+	/* use the max window size but allow the user to override it */
+	/* lastly if they disabled hpn then use the ssh std window size */
+
+	/* so why don't we just do a getsockopt() here and set the */
+	/* ssh window to that? In the case of a autotuning receive */
+	/* window the window would get stuck at the initial buffer */
+	/* size generally less than 96k. Therefore we need to set the */
+	/* maximum ssh window size to the maximum hpn buffer size */
+	/* unless the user has specifically set the tcprcvbufpoll */
+	/* to no. In which case we *can* just set the window to the */
+	/* minimum of the hpn buffer size and tcp receive buffer size */
+
+	if (tty_flag)
+		options.hpn_buffer_size = CHAN_SES_WINDOW_DEFAULT;
+	else
+		options.hpn_buffer_size = 2*1024*1024;
+
+	if (datafellows & SSH_BUG_LARGEWINDOW)
+	{
+		debug("HPN to Non-HPN Connection");
+	}
+	else
+	{
+		if (options.tcp_rcv_buf_poll <= 0)
+		{
+			sock = socket(AF_INET, SOCK_STREAM, 0);
+			getsockopt(sock, SOL_SOCKET, SO_RCVBUF,
+				   &socksize, &socksizelen);
+			close(sock);
+			debug("socksize %d", socksize);
+			options.hpn_buffer_size = socksize;
+			debug ("HPNBufferSize set to TCP RWIN: %d", options.hpn_buffer_size);
+		}
+		else
+		{
+			if (options.tcp_rcv_buf > 0)
+			{
+				/*create a socket but don't connect it */
+				/* we use that the get the rcv socket size */
+				sock = socket(AF_INET, SOCK_STREAM, 0);
+				/* if they are using the tcp_rcv_buf option */
+				/* attempt to set the buffer size to that */
+				if (options.tcp_rcv_buf)
+					setsockopt(sock, SOL_SOCKET, SO_RCVBUF, (void *)&options.tcp_rcv_buf,
+						   sizeof(options.tcp_rcv_buf));
+				getsockopt(sock, SOL_SOCKET, SO_RCVBUF,
+					   &socksize, &socksizelen);
+				close(sock);
+				debug("socksize %d", socksize);
+				options.hpn_buffer_size = socksize;
+				debug ("HPNBufferSize set to user TCPRcvBuf: %d", options.hpn_buffer_size);
+			}
+ 		}
+	}
+
+	debug("Final hpn_buffer_size = %d", options.hpn_buffer_size);
+
+	window = options.hpn_buffer_size;
+
+	channel_set_hpn(options.hpn_disabled, options.hpn_buffer_size);
+
 	packetmax = CHAN_SES_PACKET_DEFAULT;
 	if (tty_flag) {
+		window = 4*CHAN_SES_PACKET_DEFAULT;
 		window >>= 1;
 		packetmax >>= 1;
 	}
@@ -1642,6 +1710,10 @@ ssh_session2_open(void)
 	    window, packetmax, CHAN_EXTENDED_WRITE,
 	    "client-session", /*nonblock*/0);
 
+	if ((options.tcp_rcv_buf_poll > 0) && (!options.hpn_disabled)) {
+		c->dynamic_window = 1;
+		debug ("Enabled Dynamic Window Scaling");
+	}
 	debug3("ssh_session2_open: channel_new: %d", c->self);
 
 	channel_send_open(c->self);
diff --git a/sshconnect.c b/sshconnect.c
index 573d7a8..9cf6947 100644
--- a/sshconnect.c
+++ b/sshconnect.c
@@ -263,6 +263,31 @@ ssh_kill_proxy_command(void)
 }
 
 /*
+ * Set TCP receive buffer if requested.
+ * Note: tuning needs to happen after the socket is
+ * created but before the connection happens
+ * so winscale is negotiated properly -cjr
+ */
+static void
+ssh_set_socket_recvbuf(int sock)
+{
+	void *buf = (void *)&options.tcp_rcv_buf;
+	int sz = sizeof(options.tcp_rcv_buf);
+	int socksize;
+	int socksizelen = sizeof(int);
+
+	debug("setsockopt Attempting to set SO_RCVBUF to %d", options.tcp_rcv_buf);
+	if (setsockopt(sock, SOL_SOCKET, SO_RCVBUF, buf, sz) >= 0) {
+	  getsockopt(sock, SOL_SOCKET, SO_RCVBUF, &socksize, &socksizelen);
+	  debug("setsockopt SO_RCVBUF: %.100s %d", strerror(errno), socksize);
+	}
+	else
+		error("Couldn't set socket receive buffer to %d: %.100s",
+		    options.tcp_rcv_buf, strerror(errno));
+}
+
+
+/*
  * Creates a (possibly privileged) socket for use as the ssh connection.
  */
 static int
@@ -278,6 +303,9 @@ ssh_create_socket(int privileged, struct addrinfo *ai)
 	}
 	fcntl(sock, F_SETFD, FD_CLOEXEC);
 
+	if (options.tcp_rcv_buf > 0)
+		ssh_set_socket_recvbuf(sock);
+
 	/* Bind the socket to an alternative local IP address */
 	if (options.bind_address == NULL && !privileged)
 		return sock;
@@ -520,10 +548,10 @@ send_client_banner(int connection_out, int minor1)
 	/* Send our own protocol version identification. */
 	if (compat20) {
 		xasprintf(&client_version_string, "SSH-%d.%d-%.100s\r\n",
-		    PROTOCOL_MAJOR_2, PROTOCOL_MINOR_2, SSH_VERSION);
+		    PROTOCOL_MAJOR_2, PROTOCOL_MINOR_2, SSH_RELEASE);
 	} else {
 		xasprintf(&client_version_string, "SSH-%d.%d-%.100s\n",
-		    PROTOCOL_MAJOR_1, minor1, SSH_VERSION);
+		    PROTOCOL_MAJOR_1, minor1, SSH_RELEASE);
 	}
 	if (roaming_atomicio(vwrite, connection_out, client_version_string,
 	    strlen(client_version_string)) != strlen(client_version_string))
diff --git a/sshd.c b/sshd.c
index 7523de9..9623887 100644
--- a/sshd.c
+++ b/sshd.c
@@ -436,7 +436,7 @@ sshd_exchange_identification(int sock_in, int sock_out)
 	}
 
 	xasprintf(&server_version_string, "SSH-%d.%d-%.100s%s%s%s",
-	    major, minor, SSH_VERSION,
+	    major, minor, SSH_RELEASE,
 	    *options.version_addendum == '\0' ? "" : " ",
 	    options.version_addendum, newline);
 
@@ -1082,6 +1082,8 @@ server_listen(void)
 	int ret, listen_sock, on = 1;
 	struct addrinfo *ai;
 	char ntop[NI_MAXHOST], strport[NI_MAXSERV];
+	int socksize;
+	int socksizelen = sizeof(int);
 
 	for (ai = options.listen_addrs; ai; ai = ai->ai_next) {
 		if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
@@ -1122,6 +1124,11 @@ server_listen(void)
 
 		debug("Bind to port %s on %s.", strport, ntop);
 
+		getsockopt(listen_sock, SOL_SOCKET, SO_RCVBUF,
+				   &socksize, &socksizelen);
+		debug("Server TCP RWIN socket size: %d", socksize);
+		debug("HPN Buffer Size: %d", options.hpn_buffer_size);
+
 		/* Bind the socket to the desired port. */
 		if (bind(listen_sock, ai->ai_addr, ai->ai_addrlen) < 0) {
 			error("Bind to port %s on %s failed: %.200s.",
@@ -2058,6 +2065,9 @@ main(int ac, char **av)
 	    remote_ip, remote_port,
 	    get_local_ipaddr(sock_in), get_local_port());
 
+	/* set the HPN options for the child */
+	channel_set_hpn(options.hpn_disabled, options.hpn_buffer_size);
+
 	/*
 	 * We don't want to listen forever unless the other side
 	 * successfully authenticates itself.  So we set up an alarm which is
diff --git a/sshd_config b/sshd_config
index e9045bc..7495fc9 100644
--- a/sshd_config
+++ b/sshd_config
@@ -125,6 +125,17 @@ UsePrivilegeSeparation sandbox		# Default for new installations.
 # override default of no subsystems
 Subsystem	sftp	/usr/libexec/sftp-server
 
+# the following are HPN related configuration options
+# tcp receive buffer polling. disable in non autotuning kernels
+#TcpRcvBufPoll yes
+ 
+# disable hpn performance boosts
+#HPNDisabled no
+
+# buffer size for hpn to non-hpn connections
+#HPNBufferSize 2048
+
+
 # Example of overriding settings on a per-user basis
 #Match User anoncvs
 #	X11Forwarding no
diff --git a/version.h b/version.h
index a1579ac..4fe1849 100644
--- a/version.h
+++ b/version.h
@@ -3,4 +3,5 @@
 #define SSH_VERSION	"OpenSSH_6.6"
 
 #define SSH_PORTABLE	"p1"
-#define SSH_RELEASE	SSH_VERSION SSH_PORTABLE
+#define SSH_HPN         "-hpn14v4"
+#define SSH_RELEASE	SSH_VERSION SSH_PORTABLE SSH_HPN