diff --git a/ChangeLog b/ChangeLog
index 0ab8253..ee4276d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,8 +1,10 @@
 0.5.0
 =====
-   1-Nov-2003:	- siproxd can use another outbound proxy itself
+   2-Nov-2003:	- rtpproxy bugfix: On repetitive INVITES, the UDP media
+                  port could end up as -1 in the rewritten packet.
+   1-Nov-2003:	- siproxd can use another outbound proxy (chaining)
 		- Linux 2.4.x: siproxd with RTP relay could hang
-                  on termination. Fixed.
+                  on termination (Thread termination). Fixed.
                   
 
 0.4.2
diff --git a/src/proxy.c b/src/proxy.c
index 9609b86..6162ff3 100644
--- a/src/proxy.c
+++ b/src/proxy.c
@@ -600,22 +600,25 @@ if (configuration.debuglevel)
       /* start an RTP proxying stream */
       if (sdp_message_m_port_get(sdp, media_stream_no)) {
          inb_clnt_port=atoi(sdp_message_m_port_get(sdp, media_stream_no));
-         rtp_start_fwd(osip_message_get_call_id(mymsg), media_stream_no,
-                       outb_addr, &outb_rtp_port,
-	               lcl_clnt_addr, inb_clnt_port);
-         /* and rewrite the port */
-         sdp_med=osip_list_get(sdp->m_medias, media_stream_no);
-         if (sdp_med && sdp_med->m_port) {
-            osip_free(sdp_med->m_port);
-            sdp_med->m_port=osip_malloc(8);
-            sprintf(sdp_med->m_port, "%i", outb_rtp_port);
-            DEBUGC(DBCLASS_PROXY, "proxy_rewrite_invitation_body: "
-                   "m= rewrote port to [%i]",outb_rtp_port);
 
-         } else {
-            ERROR("rewriting port in m= failed sdp_med=%p, "
-                  "m_number_of_port=%p", sdp_med, sdp_med->m_port);
-         }
+         if (inb_clnt_port > 0) {
+            rtp_start_fwd(osip_message_get_call_id(mymsg), media_stream_no,
+                          outb_addr, &outb_rtp_port,
+	                  lcl_clnt_addr, inb_clnt_port);
+            /* and rewrite the port */
+            sdp_med=osip_list_get(sdp->m_medias, media_stream_no);
+            if (sdp_med && sdp_med->m_port) {
+               osip_free(sdp_med->m_port);
+               sdp_med->m_port=osip_malloc(8);
+               sprintf(sdp_med->m_port, "%i", outb_rtp_port);
+               DEBUGC(DBCLASS_PROXY, "proxy_rewrite_invitation_body: "
+                      "m= rewrote port to [%i]",outb_rtp_port);
+
+            } else {
+               ERROR("rewriting port in m= failed sdp_med=%p, "
+                     "m_number_of_port=%p", sdp_med, sdp_med->m_port);
+            }
+         } // port > 0
       } else {
          /* no port defined - skip entry */
          WARN("no port defined in m=(media) stream_no=&i", media_stream_no);
diff --git a/src/rtpproxy.c b/src/rtpproxy.c
index 9f30add..e9243d0 100644
--- a/src/rtpproxy.c
+++ b/src/rtpproxy.c
@@ -48,7 +48,9 @@ int rtpproxy_init( void ) {
       sts = STS_SUCCESS;
    } else if (configuration.rtp_proxy_enable == 1) { // Relay
       sts = rtp_relay_init ();
-   } else if (configuration.rtp_proxy_enable == 2) { // MASQ tunnels
+   } else if (configuration.rtp_proxy_enable == 2) { // MASQ tunnels (ipchains)
+      sts = rtp_masq_init ();
+   } else if (configuration.rtp_proxy_enable == 3) { // MASQ tunnels (netfilter)
       sts = rtp_masq_init ();
    } else {
       ERROR("CONFIG: rtp_proxy_enable has invalid value",
@@ -76,10 +78,14 @@ int rtp_start_fwd (osip_call_id_t *callid, int media_stream_no,
       sts = rtp_relay_start_fwd (callid, media_stream_no,
                                   outbound_ipaddr, outboundport,
                                   lcl_client_ipaddr, lcl_clientport);
-   } else if (configuration.rtp_proxy_enable == 2) { // MASQ tunnels
+   } else if (configuration.rtp_proxy_enable == 2) { // MASQ tunnels (ipchains)
       sts = rtp_masq_start_fwd (callid, media_stream_no,
                                  outbound_ipaddr, outboundport,
                                  lcl_client_ipaddr, lcl_clientport);
+   } else if (configuration.rtp_proxy_enable == 3) { // MASQ tunnels (netfilter)
+      sts = rtp_masq_start_fwd (callid, media_stream_no,
+                                   outbound_ipaddr, outboundport,
+                                   lcl_client_ipaddr, lcl_clientport);
    } else {
       ERROR("CONFIG: rtp_proxy_enable has invalid value",
             configuration.rtp_proxy_enable);
@@ -103,7 +109,9 @@ int rtp_stop_fwd (osip_call_id_t *callid) {
       sts = STS_SUCCESS;
    } else if (configuration.rtp_proxy_enable == 1) { // Relay
       sts = rtp_relay_stop_fwd(callid, 0);
-   } else if (configuration.rtp_proxy_enable == 2) { // MASQ tunnels
+   } else if (configuration.rtp_proxy_enable == 2) { // MASQ tunnels (ipchains)
+      sts = rtp_masq_stop_fwd(callid);
+   } else if (configuration.rtp_proxy_enable == 3) { // MASQ tunnels (netfilter)
       sts = rtp_masq_stop_fwd(callid);
    } else {
       ERROR("CONFIG: rtp_proxy_enable has invalid value",