--- asterisk/channels/chan_sip.c.original	2014-02-12 15:51:34.341036111 +0400
+++ asterisk/channels/chan_sip.c	2014-02-18 13:18:08.949406126 +0400
@@ -18196,7 +18196,7 @@
 		ast_string_field_set(p, peersecret, NULL);
 		ast_string_field_set(p, peermd5secret, NULL);
 	}
-	if (!(res = check_auth(p, req, peer->name, p->peersecret, p->peermd5secret, sipmethod, uri2, reliable))) {
+	if (!(res = check_auth(p, req, ast_strlen_zero(peer->fromuser) ? peer->name : peer->fromuser, p->peersecret, p->peermd5secret, sipmethod, uri2, reliable))) {
 		/* If we have a call limit, set flag */
 		if (peer->call_limit)
 			ast_set_flag(&p->flags[0], SIP_CALL_LIMIT);