--- res/res_pjsip_session.c	(Asterisk 13.18 GitHub 114602f)
+++ res/res_pjsip_session.c	(working copy)
@@ -3136,6 +3136,7 @@
 		if (ast_sip_transport_is_local(transport_state, &our_sdp_addr) || !transport_state->localnet) {
 			ast_debug(5, "Setting external media address to %s\n", ast_sockaddr_stringify_host(&transport_state->external_media_address));
 			pj_strdup2(tdata->pool, &sdp->conn->addr, ast_sockaddr_stringify_host(&transport_state->external_media_address));
+			pj_strdup2(tdata->pool, &sdp->origin.addr, ast_sockaddr_stringify_host(&transport_state->external_media_address));
 		}
 	}