diff --git a/src/core.cc b/src/core.cc
index 002783c..eadae88 100644
--- a/src/core.cc
+++ b/src/core.cc
@@ -72,7 +72,7 @@
     device_info->set_technology(technology);
     device_info->set_pon_ports(NUM_OF_PON_PORTS);
     device_info->set_onu_id_start(1);
-    device_info->set_onu_id_end(257);
+    device_info->set_onu_id_end(255);
     device_info->set_alloc_id_start(1024);
     device_info->set_alloc_id_end(16383);
     device_info->set_gemport_id_start(1024);