diff --git a/python/protos/device.proto b/python/protos/device.proto
new file mode 100644
index 0000000..cf53269
--- /dev/null
+++ b/python/protos/device.proto
@@ -0,0 +1,329 @@
+syntax = "proto3";
+
+option go_package = "github.com/opencord/voltha-protos/go/voltha";
+
+package voltha;
+
+import "meta.proto";
+import "google/protobuf/any.proto";
+import "common.proto";
+import "openflow_13.proto";
+import "yang_options.proto";
+
+
+// A Device Type
+message DeviceType {
+
+    // Unique name for the device type
+    string id = 1;
+
+    // Unique venor id for the device type applicable to ONU
+    // 4 bytes of vendor id from ONU serial number
+    string vendor_id = 5;
+
+    repeated string vendor_ids = 6;
+
+    // Name of the adapter that handles device type
+    string adapter = 2;
+
+    // Capabilitities
+
+    bool accepts_bulk_flow_update = 3;
+    bool accepts_add_remove_flow_updates = 4;
+    bool accepts_direct_logical_flows_update = 7;
+
+}
+
+// A plurality of device types
+message DeviceTypes {
+    repeated DeviceType items = 1;
+}
+
+message PmConfig {
+    enum PmType {
+        COUNTER = 0;
+        GAUGE = 1;
+        STATE = 2;
+        CONTEXT = 3;
+    }
+    string name = 1;
+    PmType type = 2;
+    bool enabled = 3; // Whether or not this metric makes it to Kafka
+    uint32 sample_freq = 4; // Sample rate in 10ths of a second
+}
+
+message PmGroupConfig {
+    string group_name = 1;
+    uint32 group_freq = 2; // Frequency applicable to the grop
+    bool enabled = 3; // Enable/disable group level only
+    repeated PmConfig metrics = 4;
+}
+
+message PmConfigs {
+    string id = 1; // To work around a chameleon POST bug
+    uint32 default_freq = 2; // Default sample rate
+    // Forces group names and group semantics
+    bool grouped = 3 [(access) = READ_ONLY];
+    // Allows Pm to set an individual sample frequency
+    bool freq_override = 4 [(access) = READ_ONLY];
+    repeated PmGroupConfig groups = 5; // The groups if grouped is true
+    repeated PmConfig metrics = 6; // The metrics themselves if grouped is false.
+}
+
+// Describes instance of software image on the device
+message Image {
+    string name = 1;                // software patch name
+    string version = 2;             // version of software
+    string hash = 3;                // md5 hash
+    string install_datetime = 4;    // combined date and time expressed in UTC.
+                                    // use ISO 8601 format for date and time
+
+    // The active software image is one that is currently loaded and executing
+    // in the ONU or circuit pack. Under normal operation, one software image
+    // is always active while the other is inactive. Under no circumstances are
+    // both software images allowed to be active at the same time
+    bool is_active = 5;             // True if the image is active
+
+    // The committed software image is loaded and executed upon reboot of the
+    // ONU and/or circuit pack. During normal operation, one software image is
+    // always committed, while the other is uncommitted.
+    bool is_committed = 6;          // True if the image is committed
+
+    // A software image is valid if it has been verified to be an executable
+    // code image. The verification mechanism is not subject to standardization;
+    // however, it should include at least a data integrity (e.g., CRC) check of
+    // the entire code image.
+    bool is_valid = 7;              // True if the image is valid
+}
+
+// List of software on the device
+message Images {
+    repeated Image image = 1;
+}
+
+message ImageDownload {
+    option (yang_child_rule) = MOVE_TO_PARENT_LEVEL;
+
+    enum ImageDownloadState {
+        DOWNLOAD_UNKNOWN = 0;
+        DOWNLOAD_SUCCEEDED = 1;
+        DOWNLOAD_REQUESTED = 2;
+        DOWNLOAD_STARTED = 3;
+        DOWNLOAD_FAILED = 4;
+        DOWNLOAD_UNSUPPORTED = 5;
+        DOWNLOAD_CANCELLED = 6;
+    }
+
+    enum ImageDownloadFailureReason {
+        NO_ERROR = 0;
+        INVALID_URL = 1;
+        DEVICE_BUSY = 2;
+        INSUFFICIENT_SPACE = 3;
+        UNKNOWN_ERROR = 4;
+        CANCELLED = 5;
+    }
+
+    enum ImageActivateState {
+        IMAGE_UNKNOWN = 0;
+        IMAGE_INACTIVE = 1;
+        IMAGE_ACTIVATE = 2;
+        IMAGE_ACTIVE = 3;
+        IMAGE_REVERT = 4;
+    }
+
+    // Device Identifier
+    string id = 1;
+
+    // Image unique identifier
+    string name = 2;
+
+    // URL where the image is available
+    // should include username password
+    string url = 3;
+
+    // CRC of the image to be verified aginst
+    uint32 crc = 4;
+
+    // Download state
+    ImageDownloadState download_state = 5;
+
+    // Downloaded version
+    string image_version = 6;
+
+    // Bytes downloaded
+    uint32 downloaded_bytes = 7;
+
+    // Download failure reason
+    ImageDownloadFailureReason reason= 8;
+
+    // Additional info
+    string additional_info = 9;
+
+    // Save current configuration
+    bool save_config = 10;
+
+    // Image local location
+    string local_dir = 11;
+
+    // Image activation state
+    ImageActivateState image_state = 12;
+    
+    // Image file size
+    uint32 file_size = 13;
+}
+
+message ImageDownloads {
+    repeated ImageDownload items = 2;
+}
+
+message Port {
+    option (voltha.yang_child_rule) = MOVE_TO_PARENT_LEVEL;
+
+    enum PortType {
+        UNKNOWN = 0;
+        ETHERNET_NNI = 1;
+        ETHERNET_UNI = 2;
+        PON_OLT = 3;
+        PON_ONU = 4;
+        VENET_OLT = 5;
+        VENET_ONU = 6;
+    }
+
+    uint32 port_no = 1;  // Device-unique port number
+
+    string label = 2;  // Arbitrary port label
+
+    PortType type = 3;  //  Type of port
+
+    AdminState.AdminState admin_state = 5;
+
+    OperStatus.OperStatus oper_status = 6;
+
+    string device_id = 7;  // Unique .id of device that owns this port
+
+    message PeerPort {
+        string device_id = 1;
+        uint32 port_no = 2;
+    }
+    repeated PeerPort peers = 8;
+
+    fixed64 rx_packets = 9;
+    fixed64 rx_bytes = 10;
+    fixed64 rx_errors = 11;
+    fixed64 tx_packets = 12;
+    fixed64 tx_bytes = 13;
+    fixed64 tx_errors = 14;
+
+}
+
+message Ports {
+    repeated Port items = 1;
+}
+
+// A Physical Device instance
+message Device {
+    option (voltha.yang_child_rule) = MOVE_TO_PARENT_LEVEL;
+
+    // Voltha's device identifier
+    string id = 1 [(access) = READ_ONLY];
+
+    // Device type, refers to one of the registered device types
+    string type = 2 [(access) = READ_ONLY];
+
+    // Is this device a root device. Each logical switch has one root
+    // device that is associated with the logical flow switch.
+    bool root = 3 [(access) = READ_ONLY];
+
+    // Parent device id, in the device tree (for a root device, the parent_id
+    // is the logical_device.id)
+    string parent_id = 4 [(access) = READ_ONLY];
+    uint32 parent_port_no = 20 [(access) = READ_ONLY];
+
+    // Vendor, version, serial number, etc.
+    string vendor = 5 [(access) = READ_ONLY];
+    string model = 6 [(access) = READ_ONLY];
+    string hardware_version = 7 [(access) = READ_ONLY];
+    string firmware_version = 8 [(access) = READ_ONLY];
+    // List of software on the device
+    Images images = 9 [(access) = READ_ONLY];
+    string serial_number = 10 [(access) = READ_ONLY];
+    string vendor_id = 24 [(access) = READ_ONLY];
+
+    // Addapter that takes care of device
+    string adapter = 11 [(access) = READ_ONLY];
+
+    // Device contact on vlan (if 0, no vlan)
+    uint32 vlan = 12;
+
+    message ProxyAddress {
+        string device_id = 1;  // Which device to use as proxy to this device
+        string device_type = 2; // The device type of the proxy device to use as the adapter name
+        uint32 channel_id = 3;  // Sub-address within proxy
+        uint32 channel_group_id = 4; // Channel Group index
+        string channel_termination = 5; // Channel Termination name
+        uint32 onu_id = 6; // onu identifier; optional
+        uint32 onu_session_id = 7; // session identifier for the ONU; optional
+    };
+
+    oneof address {
+        // Device contact MAC address (format: "xx:xx:xx:xx:xx:xx")
+        string mac_address = 13;
+
+        // Device contact IPv4 address (format: "a.b.c.d" or can use hostname too)
+        string ipv4_address = 14;
+
+        // Device contact IPv6 address using the canonical string form
+        // ("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx")
+        string ipv6_address = 15;
+
+        string host_and_port = 21;
+
+    };
+    string extra_args = 23;  // Used to pass additional device specific arguments
+
+    ProxyAddress proxy_address = 19;
+
+    AdminState.AdminState admin_state = 16;
+
+    OperStatus.OperStatus oper_status = 17 [(access) = READ_ONLY];
+
+    string reason = 22 [(access) = READ_ONLY];  //  Used in FAILED state
+
+    ConnectStatus.ConnectStatus connect_status = 18 [(access) = READ_ONLY];
+
+    // TODO additional common attribute here
+
+    // Device type specific attributes
+    google.protobuf.Any custom = 64;
+
+    repeated Port ports = 128  [(child_node) = {key: "port_no"}];
+    openflow_13.Flows flows = 129 [(child_node) = {}];
+    openflow_13.FlowGroups flow_groups = 130 [(child_node) = {}];
+    // PmConfigs will eventually converted to a child node of the
+    // device to falicitata callbacks and to simplify manipulation.
+    PmConfigs pm_configs = 131 [(child_node) = {}];
+
+    repeated ImageDownload image_downloads = 133 [(child_node) = {key: "name"}];
+}
+
+message Devices {
+    repeated Device items = 1;
+}
+
+message SimulateAlarmRequest {
+    enum OperationType {
+        RAISE = 0;
+        CLEAR = 1;
+    }
+    // Device Identifier
+    string id = 1;
+    string indicator = 2;
+    string intf_id = 3;
+    string port_type_name = 4;
+    string onu_device_id = 5;
+    int32 inverse_bit_error_rate = 6;
+    int32 drift = 7;
+    int32 new_eqd = 8;
+    string onu_serial_number = 9;
+    OperationType operation = 10;
+}