windows-itpro-docs/windows/deployment/update/delivery-optimization-workflow.md

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title	manager	description	keywords	ms.prod	ms.mktglfcycl	audience	author	ms.localizationpriority	ms.author	ms.collection	ms.topic
Understand the Delivery Optimization Client-Service Communication Explained	laurawi	Settings to use with various proxy configurations to allow Delivery Optimization to work	updates, downloads, network, bandwidth	w10	deploy	itpro	carmenf	medium	carmenf	M365-modern-desktop	article

Delivery Optimization Client-Service Communication Explained

Applies to: Windows 10

Download Request Workflow

The DO workflow described below allows Delivery Optimization to securely and efficiently deliver requested content to the calling device.

• When a download starts, the DO client will attempt to get its content metadata, from the DO service, which is a hash file containing the SHA-256 hash of each piece in the file, typically piece = 1 MB. Separate metadata that is obtained, through an SSL channel, provides DO a way to verify the authenticity of the hash file itself once it is downloaded.
• When DO pulls a certain piece of the hash from another peer, it is verified against the known hash in the hash file.
• If a peer provides an invalid piece, that piece is discarded. A peer that sends multiple bad pieces is banned and will no longer be used as a source by the client performing the download.
• If DO is unable to obtain the hash file, or the verification of the hash file itself fails, the download will fall back to “Simple Mode” (pulling content only from an HTTP source) and peer to peer will not be allowed.
• Once DO is done downloading and puts together the file from all the pieces it got, the caller using DO (ConfigMgr for example) performs yet another check for the entire file as well as verify the signature of it prior to proceeding with installation.

Delivery Optimization Service Endpoint And Data Information

Endpoint hostname	Name	Description	Data sent from the computer to the Endpoint (Field/Description)
geover-prod.do.dsp.mp.microsoft.com geo-prod.do.dsp.mp.microsoft.com geo.prod.do.dsp.mp.microsoft.com geover.prod.do.dsp.mp.microsoft.com	Geo	Service used to identify the geo location of the device in order to direct it to the nearest data center.	Profile: The device type (ex: PC vs Xbox) doClientVersion: The version of the DoSvc Client groupID: Group the device belongs to (set via DownloadMode = '2' (Group download mode) + groupID group policy / MDM policies)
kv*-prod.do.dsp.mp.microsoft.com kv*.prod.do.dsp.mp.microsoft.com	KeyValue	Bootstrap service, provides endpoints for all other services as well as device configs	countryCode: The country the client is connected from doClientVersion: The version of the DoSvc Client Profile: The device type (ex: PC vs Xbox) eId: Client grouping Id CacheHost: Cache host id<
cp*-prod.do.dsp.mp.microsoft.com cp*.prod.do.dsp.mp.microsoft.com	Content Policy	Provides content specific policies as well as content metadata URLs	Profile: The device type (ex: PC vs Xbox) ContentId: The content identifier doClientVersion: The version of the dosvc client countryCode: The country the client is connected from altCatalogId: If ContentId isn't available, use the download URL instead eId: Client grouping Id CacheHost: Cache host id
disc*-prod.do.dsp.mp.microsoft.com disc*.prod.do.dsp.mp.microsoft.com	Discovery	Provides the client with the geo-located Array to connect to. (There are two endpoints providing this functionality: /content and /v2/content)	Profile: The device type (ex: PC vs Xbox) ContentId: The content identifier doClientVersion: The version of the dosvc client partitionId: Client partitioning hint altCatalogId: If ContentId isn't available, use the download URL instead eId: Client grouping Id
cn*-prod.do.dsp.mp.microsoft.com cn*.prod.do.dsp.mp.microsoft.com	Arrays	Provides the client with list of peers that have the same content and belong to the same peer group.	Profile: The device type (ex: PC vs Xbox) ContentId: The content identifier doClientVersion: The version of the dosvc client altCatalogId: If ContentId isn't available, use the download URL instead PeerId: Identified of the device running DO client ReportedIp: The internal / private IP Address IsBackground: Is the download interactive or background Uploaded: Total bytes uploaded to peers Downloaded: Total bytes downloaded from peers DownloadedCdn: Total bytes downloaded from CDN Left: Bytes left to download Peers Wanted: Total number of peers wanted Group Id: Group the device belongs to (set via DownloadMode 2 + Group ID GP / MDM policies) Scope: The Download mode UploadedBPS: The upload speed in Bytes per Second DownloadBPS: The download speed in Bytes per second eId: Client grouping Id
dl.delivery.mp.microsoft.com emdl.ws.microsoft.com		Metadata download can come from different hostnames, however it is required for P2P