--- chan_zap.c	2008-03-10 21:27:08.000000000 +0100
+++ chan_zap.c-mod	2008-05-03 11:21:47.000000000 +0200
@@ -6147,7 +6147,7 @@
 					if (f->frametype == AST_FRAME_DTMF) {
 						dtmfbuf[i++] = f->subclass;
 						ast_log(LOG_DEBUG, "CID got digit '%c'\n", f->subclass);
-						res = 2000;
+						res = 4000;
 					}
 					ast_frfree(f);
 					if (chan->_state == AST_STATE_RING ||