Microsoft Connected Cache for ISPs: Microsoft’s distributed CDN

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This post has been republished via RSS; it originally appeared at: New blog articles in Microsoft Community Hub.

Microsoft Connected Cache for ISPs is growing in popularity. Learn how it works and what this means for Windows content downloads in your organization.

You may already know that for enterprises, a Microsoft Connected Cache server acts as an on-premises, on-demand transparent cache for content downloaded by Delivery Optimization. Did you know that Microsoft offers Microsoft Connected Cache for Internet Service Providers (ISPs) as well? Microsoft has been offering and managing a distributed CDN solution for nearly two years. In fact, more than 200 network operators in over 60 countries have currently deployed Microsoft Connected Cache servers.

As Connected Cache grows in popularity, you may notice changing traffic patterns for Windows apps and updates on your network, where Delivery Optimization downloads directly from IP addresses of Microsoft Connected Cache servers hosted by your network operator. Read on to learn how this product works and what organizations can expect to see when this product is used.

What is Microsoft Connected Cache for Internet Service Providers?

Microsoft Connected Cache for Internet Service Providers (MCC for ISP) is a software-only caching solution for Microsoft content (Microsoft Connected Cache content and services endpoints) downloaded using Delivery Optimization. Network operators such as internet service providers (ISPs), network service providers (NSPs) and Internet Exchange Points (IXPs) deploy Microsoft Connected Cache to servers within their network to help reduce the load on their backbone network. In turn, the content is downloaded from sources closer to end user devices (consumers and organizations alike)—thereby improving download reliability and speed.

How are customer devices configured to download content from an ISP cache?

As an enterprise organization using Delivery Optimization, you may be familiar with the Delivery Optimization Cache Server Hostname policy. You can set this policy to designate one or more locally deployed Microsoft Connected Cache servers to be used by Delivery Optimization. If you have deployed Microsoft Connected Cache for Configuration Manager, then you know that devices configured properly will download content from the local cache server instead of downloading content from the internet.

With MCC for ISP, the ISP that you use for connectivity or transit can deploy a Microsoft Connected Cache server to localize traffic and deliver content in-network to subscribers like you. This has the benefit of bringing the content closer to the customer, which improves download performance for customers.

Rather than an enterprise administrator configuring device policies, Microsoft’s Delivery Optimization cloud services securely provide the alternative download source. This is the same service that powers the Delivery Optimization peer-to-peer platform, a platform that is widely used by enterprises globally today. When a device connects to the internet via an ISP that hosts a Microsoft Connected Cache, the device communicates with the Delivery Optimization cloud service and is provided with the IP Address of the Microsoft Connected Cache of that ISP to connect to directly.

What happens if we have a locally deployed Microsoft Connected Cache server?

If you have deployed Microsoft Connected Cache for Configuration Manager, your devices will always attempt to download from the locally deployed cache server first. The local policy will always take precedence over the Microsoft Connected Cache for ISPs configuration. If the local cache server is unavailable, Delivery Optimization seamlessly falls back to the next HTTP source which can be hosted by multiple third-party content delivery networks (CDNs), to get the requested content.

How can I be confident that content downloaded from an ISP cache is safe?

All content is verified, whether it be Windows, Microsoft 365 apps, the Microsoft Store, or Intune. No matter the content download source—CDN, locally-deployed Microsoft Connected Cache server, ISP-deployed Microsoft Connected Cache server, or Delivery Optimization peer devices—the same security measures are taken by Microsoft to verify the content prior to installing. For more information on this, please see Windows Update security.

How can I check if my device is configured to download from a Microsoft Connected Cache deployed by an ISP?

Microsoft does not publish the IP addresses of ISP-deployed Microsoft Connected Cache servers; however, you can check whether the Delivery Optimization cloud service applied the cache configuration to your device by running the following PowerShell cmdlet:

 

 

get-DeliveryOptimizationStatus

 

 

The “CacheHost” field in the output will contain the IP Address of the Microsoft Connected Cache server if one is configured.

 

Note: If there are no active downloads or uploads, you can start a download of a free application from Windows Store such as “Microsoft Minesweeper” and run the above cmdlet one more time.

You can also perform a download test against that IP Address in the following manner in PowerShell:

 

 

Invoke-WebRequest -URI "http://<Server IP Address>/mscomtest/wuidt.gif" -Headers @{"Host"="b1.download.windowsupdate.com"}

 

 

Will downloads fail if the ISP MCC’s IP is not in the allow list for Internet traffic out of my organization’s network?

No, if Delivery Optimization cannot connect to an ISP-deployed Microsoft Connected Cache server, the download will seamlessly fall back to a CDN source and continue to download from peers in parallel if available.

Can customers control whether devices download from ISP-deployed Microsoft Connected Cache servers?

Yes. Delivery Optimization uses all available download sources to achieve the best possible content delivery experience. The client connects to either a locally deployed Microsoft Connected Cache server, or an ISP-deployed Microsoft Connected Cache server, and peers in parallel. If the desired content cannot be obtained from Microsoft Connected Cache or peers, Delivery Optimization seamlessly falls back to the CDN to get the requested content. Enterprises can trigger fallback to CDN by setting the Delivery Optimization Cache Server Hostname policy to a blank string (“ “). Alternatively, you can deploy Microsoft Connected Cache for Configuration Manager and point your devices to pull from your locally deployed cache server.

What content is delivered using Microsoft Connected Cache?

The list of supported content and endpoints that are used by Microsoft Connected Cache are available in this document: Microsoft Connected Cache content and services endpoints.


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