Index: res/res_agi.c
===================================================================
--- res/res_agi.c	(revision 248580)
+++ res/res_agi.c	(working copy)
@@ -1626,14 +1626,14 @@
 	ast_agi_send(fd, chan, "agi_version: %s\n", ast_get_version());
 
 	/* ANI/DNIS */
-	ast_agi_send(fd, chan, "agi_callerid: %s\n", S_OR(chan->cid.cid_num, "unknown"));
-	ast_agi_send(fd, chan, "agi_calleridname: %s\n", S_OR(chan->cid.cid_name, "unknown"));
+	ast_agi_send(fd, chan, "agi_callerid: %s\n", S_OR(chan->cid.cid_num, ""));
+	ast_agi_send(fd, chan, "agi_calleridname: %s\n", S_OR(chan->cid.cid_name, ""));
 	ast_agi_send(fd, chan, "agi_callingpres: %d\n", chan->cid.cid_pres);
 	ast_agi_send(fd, chan, "agi_callingani2: %d\n", chan->cid.cid_ani2);
 	ast_agi_send(fd, chan, "agi_callington: %d\n", chan->cid.cid_ton);
 	ast_agi_send(fd, chan, "agi_callingtns: %d\n", chan->cid.cid_tns);
-	ast_agi_send(fd, chan, "agi_dnid: %s\n", S_OR(chan->cid.cid_dnid, "unknown"));
-	ast_agi_send(fd, chan, "agi_rdnis: %s\n", S_OR(chan->cid.cid_rdnis, "unknown"));
+	ast_agi_send(fd, chan, "agi_dnid: %s\n", S_OR(chan->cid.cid_dnid, ""));
+	ast_agi_send(fd, chan, "agi_rdnis: %s\n", S_OR(chan->cid.cid_rdnis, ""));
 
 	/* Context information */
 	ast_agi_send(fd, chan, "agi_context: %s\n", chan->context);