diff --git a/aconfigure.ac b/aconfigure.ac
index 14f2dd3..cfa7492 100644
--- a/aconfigure.ac
+++ b/aconfigure.ac
@@ -127,6 +127,7 @@
 AC_CHECK_HEADER(malloc.h,[AC_DEFINE(PJ_HAS_MALLOC_H,1)])
 AC_CHECK_HEADER(netdb.h,[AC_DEFINE(PJ_HAS_NETDB_H,1)])
 AC_CHECK_HEADER(netinet/in.h,[AC_DEFINE(PJ_HAS_NETINET_IN_H,1)])
+AC_CHECK_HEADER(netinet/ip.h,[AC_DEFINE(PJ_HAS_NETINET_IP_H,1)])
 AC_CHECK_HEADER(setjmp.h,[AC_DEFINE(PJ_HAS_SETJMP_H,1)])
 AC_CHECK_HEADER(stdarg.h,[AC_DEFINE(PJ_HAS_STDARG_H,1)])
 AC_CHECK_HEADER(stddef.h,[AC_DEFINE(PJ_HAS_STDDEF_H,1)])
diff --git a/pjlib/include/pj/compat/os_auto.h.in b/pjlib/include/pj/compat/os_auto.h.in
index 5148138..b129237 100644
--- a/pjlib/include/pj/compat/os_auto.h.in
+++ b/pjlib/include/pj/compat/os_auto.h.in
@@ -50,6 +50,7 @@
 #undef PJ_HAS_MALLOC_H
 #undef PJ_HAS_NETDB_H
 #undef PJ_HAS_NETINET_IN_H
+#undef PJ_HAS_NETINET_IP_H
 #undef PJ_HAS_SETJMP_H
 #undef PJ_HAS_STDARG_H
 #undef PJ_HAS_STDDEF_H
diff --git a/pjlib/include/pj/compat/socket.h b/pjlib/include/pj/compat/socket.h
index e95bc12..e64afe8 100644
--- a/pjlib/include/pj/compat/socket.h
+++ b/pjlib/include/pj/compat/socket.h
@@ -52,6 +52,11 @@
 #  include <netinet/in.h>
 #endif
 
+#if defined(PJ_HAS_NETINET_IP_H) && PJ_HAS_NETINET_IP_H != 0
+/* To pull in IPTOS_* constants */
+#  include <netinet/ip.h>
+#endif
+
 #if defined(PJ_HAS_ARPA_INET_H) && PJ_HAS_ARPA_INET_H != 0
 #  include <arpa/inet.h>
 #endif
diff --git a/pjlib/include/pj/sock.h b/pjlib/include/pj/sock.h
index 7321c5d..80d2ab7 100644
--- a/pjlib/include/pj/sock.h
+++ b/pjlib/include/pj/sock.h
@@ -93,6 +93,30 @@
 extern const pj_uint16_t PJ_SOL_UDP;	/**< UDP level.	    */
 extern const pj_uint16_t PJ_SOL_IPV6;	/**< IP version 6   */
 
+
+/* IP_TOS 
+ *
+ * Note:
+ *  TOS CURRENTLY DOES NOT WORK IN Windows 2000 and above!
+ *  See http://support.microsoft.com/kb/248611
+ */
+extern const pj_uint16_t PJ_IP_TOS;	/**< IP_TOS optname in setsockopt() */
+
+
+/*
+ * IP TOS related constats.
+ *
+ * Note:
+ *  TOS CURRENTLY DOES NOT WORK IN Windows 2000 and above!
+ *  See http://support.microsoft.com/kb/248611
+ */
+extern const pj_uint16_t PJ_IPTOS_LOWDELAY;	/**< Minimize  delays	    */
+extern const pj_uint16_t PJ_IPTOS_THROUGHPUT;	/**< Optimize throughput    */
+extern const pj_uint16_t PJ_IPTOS_RELIABILITY;	/**< Optimize for reliability*/
+extern const pj_uint16_t PJ_IPTOS_MINCOST;	/**< "filler data" where slow 
+						 transmission does't matter */
+
+
 /**
  * Values to be specified as \c optname when calling #pj_sock_setsockopt() 
  * or #pj_sock_getsockopt().
diff --git a/pjlib/src/pj/sock_bsd.c b/pjlib/src/pj/sock_bsd.c
index 6174530..e75ea77 100644
--- a/pjlib/src/pj/sock_bsd.c
+++ b/pjlib/src/pj/sock_bsd.c
@@ -46,7 +46,7 @@
  * Socket types conversion.
  * The values here are indexed based on pj_sock_type
  */
-const pj_uint16_t PJ_SOCK_STREAM	= SOCK_STREAM;
+const pj_uint16_t PJ_SOCK_STREAM= SOCK_STREAM;
 const pj_uint16_t PJ_SOCK_DGRAM	= SOCK_DGRAM;
 const pj_uint16_t PJ_SOCK_RAW	= SOCK_RAW;
 const pj_uint16_t PJ_SOCK_RDM	= SOCK_RDM;
@@ -76,6 +76,37 @@
 const pj_uint16_t PJ_SOL_IPV6	= 0xFFFF;
 #endif
 
+/* IP_TOS */
+#ifdef IP_TOS
+const pj_uint16_t PJ_IP_TOS	= IP_TOS;
+#else
+const pj_uint16_t PJ_IP_TOS	= 1;
+#endif
+
+
+/* TOS settings (declared in netinet/ip.h) */
+#ifdef IPTOS_LOWDELAY
+const pj_uint16_t PJ_IPTOS_LOWDELAY	= IPTOS_LOWDELAY;
+#else
+const pj_uint16_t PJ_IPTOS_LOWDELAY	= 0x10;
+#endif
+#ifdef IPTOS_THROUGHPUT
+const pj_uint16_t PJ_IPTOS_THROUGHPUT	= IPTOS_THROUGHPUT;
+#else
+const pj_uint16_t PJ_IPTOS_THROUGHPUT	= 0x08;
+#endif
+#ifdef IPTOS_RELIABILITY
+const pj_uint16_t PJ_IPTOS_RELIABILITY	= IPTOS_RELIABILITY;
+#else
+const pj_uint16_t PJ_IPTOS_RELIABILITY	= 0x04;
+#endif
+#ifdef IPTOS_MINCOST
+const pj_uint16_t PJ_IPTOS_MINCOST	= IPTOS_MINCOST;
+#else
+const pj_uint16_t PJ_IPTOS_MINCOST	= 0x02;
+#endif
+
+
 /* optname values. */
 const pj_uint16_t PJ_SO_TYPE    = SO_TYPE;
 const pj_uint16_t PJ_SO_RCVBUF  = SO_RCVBUF;