diff --git a/sdncon/constants.py b/sdncon/constants.py
new file mode 100755
index 0000000..277344a
--- /dev/null
+++ b/sdncon/constants.py
@@ -0,0 +1,23 @@
+#
+# Copyright (c) 2013 Big Switch Networks, Inc.
+#
+# Licensed under the Eclipse Public License, Version 1.0 (the
+# "License"); you may not use this file except in compliance with the
+# License. You may obtain a copy of the License at
+#
+#      http://www.eclipse.org/legal/epl-v10.html
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied. See the License for the specific language governing
+# permissions and limitations under the License.
+#
+
+import os
+
+""" This file defines global constants for the system, and should not 
+import any other files to prevent circular dependencies.
+"""
+
+SDN_ROOT = "/opt/sdnplatform" if not 'SDN_ROOT' in os.environ else os.environ['SDN_ROOT']