Index: channels/chan_sip.c
===================================================================
--- channels/chan_sip.c	(revisión: 347968)
+++ channels/chan_sip.c	(copia de trabajo)
@@ -29351,6 +29351,10 @@
 		return 0;
 	}
 
+	/* Set default sip port for some messages if none is specified */
+	if (!ast_sockaddr_port(&internip))
+		ast_sockaddr_set_port(&internip, ast_sockaddr_port(&bindaddr));
+
 	ast_mutex_lock(&netlock);
 	if ((sipsock > -1) && (ast_sockaddr_cmp(&old_bindaddr, &bindaddr))) {
 		close(sipsock);