Merge pull request #210741 from andrewbrownmsft/andbrown090922

Adding download limits and MCC preview text

Author: v-stsavell

articles/iot-hub-device-update/connected-cache-configure.md

@@ -11,6 +11,9 @@ ms.service: iot-hub-device-update
 
 # Configure Microsoft Connected Cache for Device Update for IoT Hub
 
+> [!NOTE]
+> This information relates to a preview feature that's available for early testing and use in a production environment. This feature is fully supported but it's still in active development and may receive substantial changes until it becomes generally available.
+
 Microsoft Connected Cache (MCC) is deployed to Azure IoT Edge gateways as an IoT Edge module. Like other IoT Edge modules, environment variables and container create options are used to configure MCC modules. This article defines the environment variables and container create options that are required for a customer to successfully deploy the Microsoft Connected Cache module for use by Device Update for IoT Hub.
 
 ## Module deployment details

articles/iot-hub-device-update/connected-cache-disconnected-device-update.md

@@ -11,6 +11,9 @@ ms.service: iot-hub-device-update
 
 # Understand support for disconnected device updates
 
+> [!NOTE]
+> This information relates to a preview feature that's available for early testing and use in a production environment. This feature is fully supported but it's still in active development and may receive substantial changes until it becomes generally available.
+
 In a transparent gateway scenario, one or more devices can pass their messages through a single gateway device that maintains the connection to Azure IoT Hub. In these cases, the child devices may not have internet connectivity or may not be allowed to download content from the internet. The Microsoft Connected Cache preview IoT Edge module provides Device Update for IoT Hub customers with the capability of an intelligent in-network cache. The cache enables image-based and package-based updates of Linux OS-based devices behind an IoT Edge gateway (also called *downstream* IoT devices), and also helps reduce the bandwidth used for updates.
 
 ## Microsoft Connected Cache preview for Device Update for IoT Hub

articles/iot-hub-device-update/connected-cache-industrial-iot-nested.md

@@ -10,6 +10,9 @@ ms.service: iot-hub-device-update
 
 # Microsoft Connected Cache preview deployment scenario sample: Microsoft Connected Cache within an Azure IoT Edge for Industrial IoT configuration
 
+> [!NOTE]
+> This information relates to a preview feature that's available for early testing and use in a production environment. This feature is fully supported but it's still in active development and may receive substantial changes until it becomes generally available.
+
 Manufacturing networks are often organized in hierarchical layers following the [Purdue network model](https://en.wikipedia.org/wiki/Purdue_Enterprise_Reference_Architecture) (included in the [ISA 95](https://en.wikipedia.org/wiki/ANSI/ISA-95) and [ISA 99](https://www.isa.org/standards-and-publications/isa-standards/isa-standards-committees/isa99) standards). In these networks, only the top layer has connectivity to the cloud and the lower layers in the hierarchy can only communicate with adjacent north and south layers.
 
 This GitHub sample, [Azure IoT Edge for Industrial IoT](https://github.com/Azure-Samples/iot-edge-for-iiot), deploys the following:

articles/iot-hub-device-update/connected-cache-nested-level.md

@@ -11,6 +11,9 @@ ms.service: iot-hub-device-update
 
 # Microsoft Connected Cache preview deployment scenario sample: Two level nested Azure IoT Edge Gateway with outbound unauthenticated proxy
 
+> [!NOTE]
+> This information relates to a preview feature that's available for early testing and use in a production environment. This feature is fully supported but it's still in active development and may receive substantial changes until it becomes generally available.
+
 The diagram below describes the scenario where one Azure IoT Edge gateway has direct access to CDN resources and is acting as the parent to another Azure IoT Edge gateway. The child IoT Edge gateway is acting as the parent to an Azure IoT leaf device such as a Raspberry Pi. Both the Azure IoT Edge child and Azure IoT device are internet isolated. The example below demonstrates the configuration for two-levels of Azure IoT Edge gateways, but there is no limit to the depth of upstream hosts that Microsoft Connected Cache will support. There is no difference in Microsoft Connected Cache container create options from the previous examples.
 
 Refer to the documentation [Connect downstream IoT Edge devices - Azure IoT Edge](../iot-edge/how-to-connect-downstream-iot-edge-device.md?preserve-view=true&tabs=azure-portal&view=iotedge-2020-11) for more details on configuring layered deployments of Azure IoT Edge gateways. Additionally note that when deploying Azure IoT Edge, Microsoft Connected Cache, and custom modules, all modules must reside in the same container registry.

articles/iot-hub-device-update/connected-cache-single-level.md

@@ -11,6 +11,9 @@ ms.service: iot-hub-device-update
 
 # Microsoft Connected Cache preview deployment scenario samples
 
+> [!NOTE]
+> This information relates to a preview feature that's available for early testing and use in a production environment. This feature is fully supported but it's still in active development and may receive substantial changes until it becomes generally available.
+
 ## Single level Azure IoT Edge gateway no proxy
 
 The diagram below describes the scenario where an Azure IoT Edge gateway that has direct access to CDN resources and there is an Azure IoT leaf device such as a Raspberry PI that is an internet isolated child devices of the Azure IoT Edge gateway. 

articles/iot-hub-device-update/device-update-agent-overview.md

@@ -38,7 +38,9 @@ The Linux *platform layer* integrates with [Delivery Optimization](https://githu
 The Linux platform layer implementation can be found in the `src/platform_layers/linux_platform_layer` and it integrates with the [Delivery Optimization client](https://github.com/microsoft/do-client/releases) for downloads.
 
 This layer can integrate with different update handlers to implement the
-installers. For instance, the `SWUpdate` update handler, `Apt` update handler, and `Script` update handler.
+installers. For instance, the `SWUpdate` update handler, `Apt` update handler, and `Script` update handler.  
+
+If you choose to implement with your own downloader in place of Delivery Optimization, be sure to review the [requirements for large file downloads](device-update-limits.md).
 
 ## Update handlers
 

articles/iot-hub-device-update/device-update-limits.md

@@ -3,7 +3,7 @@ title: Understand Device Update for IoT Hub limits | Microsoft Docs
 description: Key limits for Device Update for IoT Hub.
 author: vimeht
 ms.author: vimeht
-ms.date: 7/8/2021
+ms.date: 9/9/2022
 ms.topic: conceptual
 ms.service: iot-hub-device-update
 ---
@@ -18,6 +18,11 @@ During preview, the Device Update for IoT Hub service is provided at no cost to
 
 [!INCLUDE [device-update-for-iot-hub-limits](../../includes/device-update-for-iot-hub-limits.md)]
 
+### Requirements for large-file downloads
+If you plan to deploy large-file packages, with file size larger than 100 MB, it is recommended to utilize byte range requests for a reliable download performance.  
+
+The Device Update for IoT Hub service utilizes Content Delivery Networks (CDNs) that work optimally with range requests of 1 MB in size. Range requests larger than 100 MB are not supported.
+
 ## Next steps
 
 - [Create a Device Update for IoT Hub account](create-device-update-account.md)