diff -Naur asterisk-1.2.24-orig/channels/chan_zap.c asterisk-1.2.24/channels/chan_zap.c
--- asterisk-1.2.24-orig/channels/chan_zap.c	2007-08-08 02:44:04.000000000 +0900
+++ asterisk-1.2.24/channels/chan_zap.c	2007-11-28 11:56:19.752570408 +0900
@@ -10852,6 +10852,8 @@
 					switchtype = PRI_SWITCH_EUROISDN_E1;
 				else if (!strcasecmp(v->value, "qsig"))
 					switchtype = PRI_SWITCH_QSIG;
+				else if (!strcasecmp(v->value, "ntt"))
+					switchtype = PRI_SWITCH_NTT;
 				else {
 					ast_log(LOG_ERROR, "Unknown switchtype '%s'\n", v->value);
 					ast_config_destroy(cfg);
