Index: channels/chan_sip.c
===================================================================
--- channels/chan_sip.c	(revision 338608)
+++ channels/chan_sip.c	(working copy)
@@ -9104,6 +9104,36 @@
 			    ast_rtp_lookup_mime_multiple2(s3, NULL, newnoncodeccapability, 0, 0));
 	}
 
+	/* If "nat = yes" and connection address equals "sent-by" address of
+	 * the Via header, then send RTP media to same address as SIP responses
+	 */
+	if (ast_test_flag(&p->flags[0], SIP_NAT_FORCE_RPORT) && ast_test_flag(&p->flags[1], SIP_PAGE2_SYMMETRICRTP)) {
+		char via[512];
+		char *c;
+		struct ast_sockaddr sent_by;
+
+		ast_copy_string(via, sip_get_header(req, "Via"), sizeof(via));
+
+		c = strchr(via, ' ');
+		if (c) {
+			c = ast_skip_blanks(c + 1);
+			ast_sockaddr_resolve_first(&sent_by, c, PARSE_PORT_IGNORE);
+
+			if (sa && !ast_sockaddr_cmp_addr(sa, &sent_by)) {
+				ast_sockaddr_copy(sa, &p->sa);
+			}
+			if (vsa && !ast_sockaddr_cmp_addr(vsa, &sent_by)) {
+				ast_sockaddr_copy(vsa, &p->sa);
+			}
+			if (tsa && !ast_sockaddr_cmp_addr(tsa, &sent_by)) {
+				ast_sockaddr_copy(tsa, &p->sa);
+			}
+			if (isa && !ast_sockaddr_cmp_addr(isa, &sent_by)) {
+				ast_sockaddr_copy(isa, &p->sa);
+			}
+		}
+	}
+
 	/* Setup audio address and port */
 	if (p->rtp) {
 		if (portno > 0) {