diff --git a/ChangeLog b/ChangeLog
index 8ad7cb5..8f8b554 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,6 +1,7 @@
 0.6.0
 =====
   24-May-2007:  - new feature: can masquerade User-agent header
+                - new feature: can add ;rport to my own Via Headers
   13-May-2007:  - deal with locally running UAs on same host (inboud IF side)
   07-May-2007:  - Client-ID in RTP proxy is derived from Client IP address.
                   This should fix an issue with unexpectedly timing-out RTP
diff --git a/doc/siproxd.conf.example b/doc/siproxd.conf.example
index 777af75..8f1ca30 100644
--- a/doc/siproxd.conf.example
+++ b/doc/siproxd.conf.example
@@ -243,6 +243,20 @@ debug_port = 0
 #
 #ua_string = Siproxd-UA
 
+######################################################################
+# Use ;rport in via header
+#
+# may be required in some cases where the remote SIP Registrat
+# uses asymmetric SIP signalling (you receive the SIP packets
+# from another <IP>:<port> combination than you send them to.
+# Default is disabled
+#   0 - do not add ;rport to via header
+#   1 - do add ;rport to INCOMING via header only
+#   2 - do add ;rport to OUTGOING via header only
+#   3 - do add ;rport to OUTGOING and INCOMING via headers
+#
+# use_rport = 0
+
 ######################################################################
 # Outbound proxy
 #
diff --git a/src/readconf.c b/src/readconf.c
index a7b26f5..b7c2209 100644
--- a/src/readconf.c
+++ b/src/readconf.c
@@ -184,6 +184,7 @@ static int parse_config (FILE *configfile) {
       { "pi_shortdial_akey",   TYP_STRING, &configuration.pi_shortdial_akey },
       { "pi_shortdial_entry",  TYP_STRINGA,&configuration.pi_shortdial_entry },
       { "ua_string",           TYP_STRING, &configuration.ua_string },
+      { "use_rport",           TYP_INT4,   &configuration.use_rport },
       {0, 0, 0}
    };
 
diff --git a/src/sip_utils.c b/src/sip_utils.c
index 66f970a..223b6e6 100644
--- a/src/sip_utils.c
+++ b/src/sip_utils.c
@@ -548,17 +548,31 @@ int sip_add_myvia (sip_ticket_t *ticket, int interface) {
    int sts;
    char branch_id[VIA_BRANCH_SIZE];
    char *myaddr;
+   int  add_rport=0;
 
    if (get_interface_ip(interface, &addr) != STS_SUCCESS) {
       return STS_FAILURE;
    }
 
+   /* evaluate if we need to include an ;rport */
+   /* incoming */
+   if ((configuration.use_rport & 1) && 
+       ((ticket->direction==REQTYP_INCOMING) || 
+        (ticket->direction==RESTYP_INCOMING)) ) {
+        add_rport=1;
+   } else if ((configuration.use_rport & 2) && 
+       ((ticket->direction==REQTYP_OUTGOING) || 
+        (ticket->direction==RESTYP_OUTGOING)) ) {
+        add_rport=1;
+   }
+
    sts = sip_calculate_branch_id(ticket, branch_id);
 
    myaddr=utils_inet_ntoa(addr);
-   sprintf(tmp, "SIP/2.0/UDP %s:%i;branch=%s",
+   sprintf(tmp, "SIP/2.0/UDP %s:%i;branch=%s%s",
            myaddr, configuration.sip_listen_port,
-           branch_id);
+           branch_id,
+           (add_rport)? ";rport":"");
 
    DEBUGC(DBCLASS_BABBLE,"adding VIA:%s",tmp);
 
diff --git a/src/siproxd.h b/src/siproxd.h
index 9f6917f..94302a4 100644
--- a/src/siproxd.h
+++ b/src/siproxd.h
@@ -95,6 +95,7 @@ struct siproxd_config {
    char *pi_shortdial_akey;
    stringa_t pi_shortdial_entry;
    char *ua_string;
+   int   use_rport;
 };
 
 /*