--- asterisk-rHEAD/channels/chan_sip.c.orig	2010-07-16 13:17:22.000000000 -0600
+++ asterisk-rHEAD/channels/chan_sip.c	2010-07-16 13:38:46.000000000 -0600
@@ -26754,6 +26754,8 @@ static int reload_config(enum channelrel
 					"Invalid address for externip keyword: %s\n",
 					v->value);
 			}
+			if (!ast_sockaddr_port(&externip))
+				ast_sockaddr_set_port(&externip, STANDARD_SIP_PORT);
 			externexpire = 0;
 		} else if (!strcasecmp(v->name, "externhost")) {
 			ast_copy_string(externhost, v->value, sizeof(externhost));