+OVS_URL = "http://openvswitch.org/releases/openvswitch-2.9.2.tar.gz"
+QUAGGA_URL = "{}/sdnvpn/quagga/quagga-4.tar.gz".format(OPNFV_ARTIFACTS)
+CALIPSO_INSTALLER_URL = "https://raw.githubusercontent.com/opnfv/calipso" \
+ "/master/app/install/calipso-installer.py"