diff --git a/forward.h b/forward.h
index 585991ca6f..3f4cf9e30e 100644
--- a/forward.h
+++ b/forward.h
@@ -1,4 +1,5 @@
 /*
+ * Copyright (C) 2008-2025 OpenSIPS Project
  * Copyright (C) 2001-2003 FhG Fokus
  *
  * This file is part of opensips, a free SIP server.
@@ -15,16 +16,7 @@
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
- *
- * History:
- * -------
- *  2001-??-?? created by andrei
- *  ????-??-?? lots of changes by a lot of people
- *  2003-02-11 added inline msg_send (andrei)
- *  2003-04-07 changed all ports to host byte order (andrei)
- *  2003-04-12  FORCE_RPORT_T added (andrei)
- *  2003-04-15  added tcp_disable support (andrei)
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 /*!
@@ -48,13 +40,27 @@
 #include "socket_info.h"
 
 const struct socket_info* get_send_socket(struct sip_msg* msg,
-									const union sockaddr_union* su, int proto);
-const struct socket_info* get_out_socket(const union sockaddr_union* to, int proto);
+		const union sockaddr_union* su, int proto);
+
+const struct socket_info* get_out_socket(const union sockaddr_union* to,
+		int proto);
+
 int check_self(str* host, unsigned short port, unsigned short proto);
+
+/*! \brief checks if the proto:host:port is one of the address we listen on
+ *
+ * if port==0, the  port number is expended to default
+ * if proto==0 (PROTO_NONE) the protocol is considered UDP
+ * returns 1 if true, 0 if false, -1 on error
+ */
+#define check_self_strict( _host, _port, _proto) \
+	check_self(_host,_port?_port:protos[_proto?_proto:PROTO_UDP].default_port,\
+		_proto?_proto:PROTO_UDP)
+
 int forward_request( struct sip_msg* msg,  struct proxy_l* p);
+
 int update_sock_struct_from_via( union sockaddr_union* to,
-								 struct sip_msg* msg,
-								 struct via_body* via );
+	 struct sip_msg* msg, struct via_body* via );
 
 /*! \brief use src_ip, port=src_port if rport, via port if via port, 5060 otherwise */
 #define update_sock_struct_from_ip(  to, msg ) \
diff --git a/modules/b2b_entities/dlg.c b/modules/b2b_entities/dlg.c
index ddcb35d6f0..e163d67743 100644
--- a/modules/b2b_entities/dlg.c
+++ b/modules/b2b_entities/dlg.c
@@ -713,6 +713,7 @@ int b2b_register_cb(b2b_cb_t cb, int cb_type, str *mod_name)
 	return 0;
 }
 
+
 int b2b_prescript_f(struct sip_msg *msg, void *uparam)
 {
 	str b2b_key;
@@ -766,8 +767,7 @@ int b2b_prescript_f(struct sip_msg *msg, void *uparam)
 				rt->nameaddr.uri.len,rt->nameaddr.uri.s);
 			return SCB_RUN_ALL;
 		}
-		if (check_self( &puri.host, puri.port_no?puri.port_no:SIP_PORT,
-		puri.proto?puri.proto:PROTO_UDP)!= 1 ) {
+		if (check_self_strict( &puri.host, puri.port_no, puri.proto)!= 1 ) {
 			LM_DBG("First Route uri is not mine\n");
 			return SCB_RUN_ALL;  /* not for b2b */
 
@@ -785,13 +785,12 @@ int b2b_prescript_f(struct sip_msg *msg, void *uparam)
 			}
 		}
 		if (rt) {
-			if ( parse_uri(rt->nameaddr.uri.s,rt->nameaddr.uri.len,&puri)!=0 ) {
+			if ( parse_uri(rt->nameaddr.uri.s,rt->nameaddr.uri.len,&puri)!=0 ){
 				LM_ERR("Second route uri is not valid <%.*s>\n",
 					rt->nameaddr.uri.len,rt->nameaddr.uri.s);
 				return SCB_RUN_ALL;
 			}
-			if (check_self( &puri.host, puri.port_no?puri.port_no:SIP_PORT,
-			puri.proto?puri.proto:PROTO_UDP)!= 1 ) {
+			if (check_self_strict( &puri.host, puri.port_no, puri.proto)!= 1 ){
 				LM_DBG("Second Route uri is not mine\n");
 				return SCB_RUN_ALL;  /* not for b2b */
 			}
@@ -822,7 +821,7 @@ int b2b_prescript_f(struct sip_msg *msg, void *uparam)
 	if(method_value!= METHOD_CANCEL)
 	{
 		LM_DBG("<uri> host:port [%.*s][%d]\n", host.len, host.s, port);
-		if (!check_self( &host, port ? port : SIP_PORT, msg->rcv.proto))
+		if (check_self_strict( &host, port, msg->parsed_uri.proto)!= 1 )
 		{
 			LM_DBG("RURI does not point to me\n");
 			return SCB_RUN_ALL;