The key difference for Windows' Delivery Optimization and traditional P2P is that it's only enabled by default on the Enterprise, Pro and Education SKUs, and then only enabled for connections on the same local network.
And adding to the fun, the one thing I wish it would cache, namely Xbox Game Pass downloads, you can't force it to cache or share on the LAN.
And adding to the fun, the one thing I wish it would cache, namely Xbox Game Pass downloads, you can't force it to cache or share on the LAN.