diff --git a/internal/pkg/commands/funcmap.go b/internal/pkg/commands/funcmap.go
new file mode 100644
index 0000000..4749915
--- /dev/null
+++ b/internal/pkg/commands/funcmap.go
@@ -0,0 +1,157 @@
+/*
+ * Copyright 2019-present Ciena Corporation
+ *
+ * Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
+ *
+ * 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.
+ */
+package commands
+
+import (
+	"fmt"
+	"github.com/fullstorydev/grpcurl"
+	"github.com/golang/protobuf/proto"
+	descpb "github.com/golang/protobuf/protoc-gen-go/descriptor"
+)
+
+type MethodNotFoundError struct {
+	Name string
+}
+
+func (e *MethodNotFoundError) Error() string {
+	return fmt.Sprintf("Method '%s' not found in function map", e.Name)
+}
+
+type MethodVersionNotFoundError struct {
+	Name    string
+	Version string
+}
+
+func (e *MethodVersionNotFoundError) Error() string {
+	return fmt.Sprintf("Method '%s' does not have a verison for '%s' specfied in function map", e.Name, e.Version)
+}
+
+type DescriptorNotFoundError struct {
+	Version string
+}
+
+func (e *DescriptorNotFoundError) Error() string {
+	return fmt.Sprintf("Protocol buffer descriptor for API version '%s' not found", e.Version)
+}
+
+type UnableToParseDescriptorErrror struct {
+	err     error
+	Version string
+}
+
+func (e *UnableToParseDescriptorErrror) Error() string {
+	return fmt.Sprintf("Unable to parse protocal buffer descriptor for version '%s': %s", e.Version, e.err)
+}
+
+var descriptorMap = map[string][]byte{
+	"v1": V1Descriptor,
+	"v2": V2Descriptor,
+}
+
+var functionMap = map[string]map[string]string{
+	"version": {
+		"v1": "voltha.VolthaGlobalService/GetVoltha",
+		"v2": "voltha.VolthaService/GetVoltha",
+	},
+	"adapter-list": {
+		"v1": "voltha.VolthaGlobalService/ListAdapters",
+		"v2": "voltha.VolthaService/ListAdapters",
+	},
+	"device-list": {
+		"v1": "voltha.VolthaGlobalService/ListDevices",
+		"v2": "voltha.VolthaService/ListDevices",
+	},
+	"device-ports": {
+		"v1": "voltha.VolthaGlobalService/ListDevicePorts",
+		"v2": "voltha.VolthaService/ListDevicePorts",
+	},
+	"device-create": {
+		"v1": "voltha.VolthaGlobalService/CreateDevice",
+		"v2": "voltha.VolthaService/CreateDevice",
+	},
+	"device-delete": {
+		"v1": "voltha.VolthaGlobalService/DeleteDevice",
+		"v2": "voltha.VolthaService/DeleteDevice",
+	},
+	"device-enable": {
+		"v1": "voltha.VolthaGlobalService/EnableDevice",
+		"v2": "voltha.VolthaService/EnableDevice",
+	},
+	"device-disable": {
+		"v1": "voltha.VolthaGlobalService/DisableDevice",
+		"v2": "voltha.VolthaService/DisableDevice",
+	},
+	"device-reboot": {
+		"v1": "voltha.VolthaGlobalService/RebootDevice",
+		"v2": "voltha.VolthaService/RebootDevice",
+	},
+	"device-inspect": {
+		"v1": "voltha.VolthaGlobalService/GetDevice",
+		"v2": "voltha.VolthaService/GetDevice",
+	},
+	"device-flow-list": {
+		"v1": "voltha.VolthaGlobalService/ListDeviceFlows",
+		"v2": "voltha.VolthaService/ListDeviceFlows",
+	},
+	"logical-device-list": {
+		"v1": "voltha.VolthaGlobalService/ListLogicalDevices",
+		"v2": "voltha.VolthaService/ListLogicalDevices",
+	},
+	"logical-device-ports": {
+		"v1": "voltha.VolthaGlobalService/ListLogicalDevicePorts",
+		"v2": "voltha.VolthaService/ListLogicalDevicePorts",
+	},
+	"logical-device-flow-list": {
+		"v1": "voltha.VolthaGlobalService/ListLogicalDeviceFlows",
+		"v2": "voltha.VolthaService/ListLogicalDeviceFlows",
+	},
+	"logical-device-inspect": {
+		"v1": "voltha.VolthaGlobalService/GetLogicalDevice",
+		"v2": "voltha.VolthaService/GetLogicalDevice",
+	},
+	"devicegroup-list": {
+		"v1": "voltha.VolthaGlobalService/ListDeviceGroups",
+		"v2": "voltha.VolthaService/ListDeviceGroups",
+	},
+}
+
+func GetMethod(name string) (grpcurl.DescriptorSource, string, error) {
+	version := GlobalConfig.ApiVersion
+	f, ok := functionMap[name]
+	if !ok {
+		return nil, "", &MethodNotFoundError{name}
+	}
+	m, ok := f[version]
+	if !ok {
+		return nil, "", &MethodVersionNotFoundError{name, version}
+	}
+	filename, ok := descriptorMap[version]
+	if !ok {
+		return nil, "", &DescriptorNotFoundError{version}
+	}
+
+	var fds descpb.FileDescriptorSet
+	err := proto.Unmarshal(filename, &fds)
+	if err != nil {
+		return nil, "", &UnableToParseDescriptorErrror{err, version}
+	}
+	desc, err := grpcurl.DescriptorSourceFromFileDescriptorSet(&fds)
+	if err != nil {
+		return nil, "", err
+	}
+
+	return desc, m, nil
+}