The well-known Windows Update (WU) relies on Microsoft cloud servers to patch and upgrade your systems. Upgrades are installed as they are released (subject to throttling in waves). To reduce load on the servers and speed up delivery, optimization for peer-to-peer (P2P) distribution is used since first version of Windows 10. This update method is the only option for Windows 10 Home. Both, Windows 10 Home and Windows 10 S SKUs, do not support domain joining. Windows 10 Home has very limited MDM capabilities, Windows 10 S can be managed and patched by a MDM solution. The options for P2P can be changed in GUI under Settings | Windows Update | Advanced options | Delivery Optimization:

Windows 10 1709 introduced two new GUI entries Advanced options and Activity monitor. With Advanced options you can now specify exact limits for download and upload bandwidth and define a Monthly upload limit including an info graphic showing how much is left. Bandwidth can be set between minimum a 5% and a maximum 100%, upload limit can be set between a minimum 5 GB and maximum 500 GB. Before 1709, these settings were only available via GPO:

If you have an internet rate with a monthly traffic volume or only a limited traffic volume with high speed bandwidth you should set P2P to download only from local PCs. By setting this option you block uploading to the internet. If you leave it at download from local network and internet, you should configure the monthly upload limit. The option to download only from local PCs which are in the same subnet (Group download mode in GPO) is not available via GUI.

To see the benefits of downloading from other PCs you can use the new Activity monitor. It will display download statistics for how much content is downloaded from Microsoft WU directly, from PCs on the local network and from PCs in the internet (if enabled). It also shows upload statistics for PCs in the local network and PCs in the internet (again if enabled). And last but not least some download speed statistics. The statistics are reset monthly:

If you are using a domain join capable Windows 10 version like Pro, for Workstation, Enterprise or Education, you can define all these and even more fine granular settings by GPO. You will find the relevant settings under Computer Settings | Administrative Templates | Windows Components | Delivery Optimization:

With Windows 10 1709 these settings were again extended. Now you can define Delivery Optimization In-Network Cache (DOINC) server via GPO. At the time of writing this book there was no documentation for DOINC available. Please see TechNet documentation for further information about DOINC and its benefits as soon as information is released.

Beside all these fine tuning settings the most important setting in this section will still remain on Download mode. With this GPO you can disable the new Delivery Optimization completely (Bypass) and use old Background Intelligent Transfer Service (BITS) instead, you can limit Delivery Optimization to use only HTTP download without peering (HTTP only), to use internet and local PCs (Internet), to use local PCs only when behind same NAT (LAN), to use local PCs only within same AD site (if exist) or same domain (Group).

By selecting the Simple option you use only HTTP but without contacting the Delivery Optimization cloud service. Most enterprise customers decide to use LAN or Group option to prohibit upload: