diff --git a/libs/sofia-sip/libsofia-sip-ua/docs/conformance.docs b/libs/sofia-sip/libsofia-sip-ua/docs/conformance.docs
index 351f062962..af392237a6 100644
--- a/libs/sofia-sip/libsofia-sip-ua/docs/conformance.docs
+++ b/libs/sofia-sip/libsofia-sip-ua/docs/conformance.docs
@@ -43,6 +43,7 @@ below.
 <a href="#3892">RFC 3892</a> <br>
 <a href="#3903">RFC 3903</a> <br>
 <a href="#4028">RFC 4028</a> <br>
+<a href="#4320">RFC 4320</a> <br>
 <a href="#4566">RFC 4566</a> <br>
 </td><td>
 <a href="#2327">RFC 2327</a> <br>
@@ -849,9 +850,11 @@ below.
         The session-expires value and refreshing party is negotiated in
 	<a href="nua/index.html">user-agent engine</a>. When user-agent
 	engine is responsible for refreshes, it will initiate re-INVITE or
-	UPDATE transaction at regular intervals. If there has been no SIP
-	activity in session during the refresh period, it will try to
-	automatically terminate the call by sending a @b BYE request.
+	UPDATE transaction at regular intervals.
+
+	If there has been no SIP activity in session during the refresh
+	period, it will try to automatically terminate the call by sending a
+	@b BYE request.
 
         The SIP headers explicitly supported (generating, parsing and
 	syntax checking) are @ref sip_session_expires "Session-Expires" ("x") and
@@ -861,6 +864,29 @@ below.
 	&nbsp;
     </td>
 </tr>
+
+<tr valign=top>
+    <th align="left">
+	<a name="4320"></a>
+	@RFC4320: Actions Addressing Identified Issues with SIP's Non-INVITE Transaction
+    </th>
+    <td>
+	The action 1 (make the best use of provisional responses) is
+	supported when NTATAG_EXTRA_100(1) is used with nua_create() or
+	nta_agent_create(). The 100 Trying provisional response is sent
+	after T2 is expired or when a retransmission is received after T2/2
+        after the initial request.
+
+	The action 2 (remove the useless late-response storm) is supported
+	by default. The 408 timeout response is not forwarded by default (it's
+	forwarding can be enabled with NTATAG_PASS_408(1), however).
+    </td>
+    <td>
+        Application must include NTATAG_EXTRA_100(1) with nua_create() or
+	nta_agent_create() tags.
+    </td>
+</tr>
+
 </table>
 
 <table border=1 cellpadding=4 cellspacing=0>
diff --git a/libs/sofia-sip/libsofia-sip-ua/tport/tport.c b/libs/sofia-sip/libsofia-sip-ua/tport/tport.c
index 52ee051872..52e9ce21d1 100644
--- a/libs/sofia-sip/libsofia-sip-ua/tport/tport.c
+++ b/libs/sofia-sip/libsofia-sip-ua/tport/tport.c
@@ -1482,6 +1482,8 @@ int tport_bind_server(tport_master_t *mr,
   unsigned short step = 0;
 
   bind6only_check(mr);
+
+  (void)hostname;
   
   SU_DEBUG_5(("%s(%p) to " TPN_FORMAT "\n", __func__, (void *)mr, TPN_ARGS(tpn)));
 
diff --git a/libs/sofia-sip/libsofia-sip-ua/tport/tport_type_sctp.c b/libs/sofia-sip/libsofia-sip-ua/tport/tport_type_sctp.c
index 047d91ca71..c871381fca 100644
--- a/libs/sofia-sip/libsofia-sip-ua/tport/tport_type_sctp.c
+++ b/libs/sofia-sip/libsofia-sip-ua/tport/tport_type_sctp.c
@@ -96,8 +96,8 @@ static int tport_sctp_init_socket(tport_primary_t *pri,
 				  int socket,
 				  char const **return_reason);
 static int tport_recv_sctp(tport_t *self);
-static int tport_send_sctp(tport_t const *self, msg_t *msg,
-			   msg_iovec_t iov[], int iovused);
+static ssize_t tport_send_sctp(tport_t const *self, msg_t *msg,
+			       msg_iovec_t iov[], size_t iovused);
 
 tport_vtable_t const tport_sctp_client_vtable =
 {
@@ -254,8 +254,8 @@ int tport_recv_sctp(tport_t *self)
   return 2;
 }
 
-static int tport_send_sctp(tport_t const *self, msg_t *msg,
-			   msg_iovec_t iov[], int iovused)
+static ssize_t tport_send_sctp(tport_t const *self, msg_t *msg,
+			       msg_iovec_t iov[], size_t iovused)
 {