Non-GSMA eSIM discovery support

In Windows 11 24H2, support was added for OEMs to add custom eSIM SM-DS (or SM-DP+) server addresses to their device images. OEMs can modify their device images to add non-GSMA SM-DS addresses.

Required OEM changes

For an OEM to provision a custom SM-DS address, they can add registry customization under the path: $(hklm.software)\Microsoft\Wlpasvc\OEM\eUICCs\DiscoveryServers\Default\<SM-DS_Address>

Windows behaviors with multiple SM-DS

• On devices where custom addresses have been added, Windows will make discovery requests in the following order:

  • Addresses defined by the IT Admin (applied via provisioning package)
  • Addresses defined by OEM
  • Address defined on the eUICC (typically this is the root GSMA address)

• Requests will be made to all servers, this is not customizable.

• If an eSIM profile is available from one of the servers, it will be downloaded before the request is made to the next one. If multiple profiles are downloaded from a discovery request during OOBE, the first profile downloaded will be enabled. If multiple profiles are downloaded from a discovery request from settings, the user will be able to select with profile to enable.

Recommendations:

• Windows recommends for best performance, OEMs should keep the number of custom DS addresses to 5.
• OEMs should modify both their device and recovery images at the time of manufacturing. For edge cases (like adding server addresses on devices already manufactured) the OEM should reach out to Windows directly for guidance.
• Discovery is best as an out of box experience. If an in-market device image does not contain the necessary custom DS address, Windows recommends utilizing another device activation method. Such as Mobile Plans, QR Code scanning from the camera app, or sharing an "lpa:" link with the activation code. The mobile operator can share a link to the user's device, via email or web page, in the format lpa:<activationcode> (This is the same string contained in an eSIM QR code).