diff --git a/openbsc/include/openbsc/mgcp_internal.h b/openbsc/include/openbsc/mgcp_internal.h
index 485a124..f97292d 100644
--- a/openbsc/include/openbsc/mgcp_internal.h
+++ b/openbsc/include/openbsc/mgcp_internal.h
@@ -320,3 +320,17 @@
 int mgcp_parse_sdp_data(struct mgcp_endpoint *endp, struct mgcp_rtp_end *rtp, struct mgcp_parse_data *p);
 int mgcp_set_audio_info(void *ctx, struct mgcp_rtp_codec *codec,
 			int payload_type, const char *audio_name);
+
+
+/**
+ * Internal network related
+ */
+static inline const char *mgcp_net_src_addr(struct mgcp_endpoint *endp)
+{
+	return endp->cfg->source_addr;
+}
+
+static inline const char *mgcp_bts_src_addr(struct mgcp_endpoint *endp)
+{
+	return endp->cfg->source_addr;
+}
diff --git a/openbsc/src/libmgcp/mgcp_network.c b/openbsc/src/libmgcp/mgcp_network.c
index 07e1515..c39b627 100644
--- a/openbsc/src/libmgcp/mgcp_network.c
+++ b/openbsc/src/libmgcp/mgcp_network.c
@@ -912,19 +912,20 @@
 	return ret != 0;
 }
 
-static int bind_rtp(struct mgcp_config *cfg, struct mgcp_rtp_end *rtp_end, int endpno)
+static int bind_rtp(struct mgcp_config *cfg, const char *source_addr,
+			struct mgcp_rtp_end *rtp_end, int endpno)
 {
-	if (mgcp_create_bind(cfg->source_addr, &rtp_end->rtp,
+	if (mgcp_create_bind(source_addr, &rtp_end->rtp,
 			     rtp_end->local_port) != 0) {
 		LOGP(DMGCP, LOGL_ERROR, "Failed to create RTP port: %s:%d on 0x%x\n",
-		       cfg->source_addr, rtp_end->local_port, endpno);
+		       source_addr, rtp_end->local_port, endpno);
 		goto cleanup0;
 	}
 
-	if (mgcp_create_bind(cfg->source_addr, &rtp_end->rtcp,
+	if (mgcp_create_bind(source_addr, &rtp_end->rtcp,
 			     rtp_end->local_port + 1) != 0) {
 		LOGP(DMGCP, LOGL_ERROR, "Failed to create RTCP port: %s:%d on 0x%x\n",
-		       cfg->source_addr, rtp_end->local_port + 1, endpno);
+		       source_addr, rtp_end->local_port + 1, endpno);
 		goto cleanup1;
 	}
 
@@ -961,7 +962,8 @@
 
 static int int_bind(const char *port,
 		    struct mgcp_rtp_end *end, int (*cb)(struct osmo_fd *, unsigned),
-		    struct mgcp_endpoint *_endp, int rtp_port)
+		    struct mgcp_endpoint *_endp,
+		    const char *source_addr, int rtp_port)
 {
 	if (end->rtp.fd != -1 || end->rtcp.fd != -1) {
 		LOGP(DMGCP, LOGL_ERROR, "Previous %s was still bound on %d\n",
@@ -974,32 +976,35 @@
 	end->rtp.data = _endp;
 	end->rtcp.data = _endp;
 	end->rtcp.cb = cb;
-	return bind_rtp(_endp->cfg, end, ENDPOINT_NUMBER(_endp));
+	return bind_rtp(_endp->cfg, source_addr, end, ENDPOINT_NUMBER(_endp));
 }
 
-
 int mgcp_bind_bts_rtp_port(struct mgcp_endpoint *endp, int rtp_port)
 {
 	return int_bind("bts-port", &endp->bts_end,
-			rtp_data_bts, endp, rtp_port);
+			rtp_data_bts, endp,
+			mgcp_bts_src_addr(endp), rtp_port);
 }
 
 int mgcp_bind_net_rtp_port(struct mgcp_endpoint *endp, int rtp_port)
 {
 	return int_bind("net-port", &endp->net_end,
-			rtp_data_net, endp, rtp_port);
+			rtp_data_net, endp,
+			mgcp_net_src_addr(endp), rtp_port);
 }
 
 int mgcp_bind_trans_net_rtp_port(struct mgcp_endpoint *endp, int rtp_port)
 {
 	return int_bind("trans-net", &endp->trans_net,
-			rtp_data_trans_net, endp, rtp_port);
+			rtp_data_trans_net, endp,
+			endp->cfg->source_addr, rtp_port);
 }
 
 int mgcp_bind_trans_bts_rtp_port(struct mgcp_endpoint *endp, int rtp_port)
 {
 	return int_bind("trans-bts", &endp->trans_bts,
-			rtp_data_trans_bts, endp, rtp_port);
+			rtp_data_trans_bts, endp,
+			endp->cfg->source_addr, rtp_port);
 }
 
 int mgcp_free_rtp_port(struct mgcp_rtp_end *end)
diff --git a/openbsc/src/libmgcp/mgcp_protocol.c b/openbsc/src/libmgcp/mgcp_protocol.c
index 40ea791..717c1fc 100644
--- a/openbsc/src/libmgcp/mgcp_protocol.c
+++ b/openbsc/src/libmgcp/mgcp_protocol.c
@@ -275,7 +275,7 @@
 	char osmux_extension[strlen("\nX-Osmux: 255") + 1];
 
 	if (!addr)
-		addr = endp->cfg->source_addr;
+		addr = mgcp_net_src_addr(endp);
 
 	if (endp->osmux.state == OSMUX_STATE_ACTIVATING)
 		sprintf(osmux_extension, "\nX-Osmux: %u", endp->osmux.cid);
@@ -1389,8 +1389,7 @@
 	if (len < 0)
 		return;
 
-	nchars = write_response_sdp(endp, buf + len, sizeof(buf) + len - 1,
-				    endp->cfg->source_addr);
+	nchars = write_response_sdp(endp, buf + len, sizeof(buf) + len - 1, NULL);
 	if (nchars < 0)
 		return;
 
diff --git a/openbsc/src/osmo-bsc_nat/bsc_mgcp_utils.c b/openbsc/src/osmo-bsc_nat/bsc_mgcp_utils.c
index f04c981..f19cb4c 100644
--- a/openbsc/src/osmo-bsc_nat/bsc_mgcp_utils.c
+++ b/openbsc/src/osmo-bsc_nat/bsc_mgcp_utils.c
@@ -269,7 +269,7 @@
 		       "\r\n"
 		       "c=IN IP4 %s\r\n"
 		       "m=audio %d RTP/AVP 255\r\n",
-		       port, bsc->nat->mgcp_cfg->source_addr,
+		       port, mgcp_bts_src_addr(endp),
 		       endp->bts_end.local_port);
 	if (len < 0) {
 		LOGP(DMGCP, LOGL_ERROR, "snprintf for MDCX failed.\n");
@@ -550,7 +550,7 @@
 
 	/* we need to generate a new and patched message */
 	bsc_msg = bsc_mgcp_rewrite((char *) nat->mgcp_msg, nat->mgcp_length,
-				   sccp->bsc_endp, nat->mgcp_cfg->source_addr,
+				   sccp->bsc_endp, mgcp_bts_src_addr(mgcp_endp),
 				   mgcp_endp->bts_end.local_port, osmux_cid,
 				   &mgcp_endp->net_end.codec.payload_type,
 				   nat->sdp_ensure_amr_mode_set);
@@ -745,7 +745,7 @@
 	 * with the value of 0 should be no problem.
 	 */
 	output = bsc_mgcp_rewrite((char * ) msg->l2h, msgb_l2len(msg), -1,
-				  bsc->nat->mgcp_cfg->source_addr,
+				  mgcp_net_src_addr(endp),
 				  endp->net_end.local_port, -1,
 				  &endp->bts_end.codec.payload_type,
 				  bsc->nat->sdp_ensure_amr_mode_set);