A host supports all devices with an announced MBIMEx version at or below the host's native MBIMEx version. Therefore the host will not send a MBIM_CID_VERSION message and assumes that the device's native MBIMEx version is 1.0.įeature-wise, a higher MBIMEx version is a superset of all lower MBIMEx versions.

If the device doesn't support MBIM_CID_VERSION, it will not respond to the MBIM_CID_DEVICE_SERVICES query with MBIM_CID_VERSION. If the first CID that the device receives from the host after it responds to the MBIM_CID_DEVICE_SERVICES query is any other CID, then the device assumes that the host's native MBIMEx version is 1.0.

If the first CID that the device receives from the host after it responds to the MBIM_CID_DEVICE_SERVICES query is MBIM_CID_VERSION, the device knows the host's MBIMEx version. Meanwhile, a host that does understand MBIM_CID_VERSION and has a native MBIMEx version of 2.0 or higher sends a MBIM_CID_VERSION message to the device with the host's native MBIMEx version, and the CID is the first CID that is sent to the device after receiving the MBIM_CID_DEVICE_SERVICES response. If a device supports MBIM_CID_VERSION and advertises its support in the MBIM_CID_DEVICE_SERVICES query response, then a host that does not understand MBIM_CID_VERSION or has an MBIMEx version lower than 2.0 ignores it. In any release, the host always queries the device for supported services and CIDs using MBIM_CID_DEVICE_SERVICES at the beginning of the device initialization sequence. Devices can learn the host's MBIMEx version explicitly only via the MBIM_CID_VERSION message. A device's announced MBIMEx version can be lower than its native MBIMEx version, which is the highest MBIMEx version that the device supports. The higher MBIMEx version is referred to as the device's announced MBIMEx version. If these two are different, the higher version dictates the MBIMEx version for the duration that the device stays enumerated to the host.

The optional MBM_CID_VERSION message, if the device supports it and declares support for it.

The MBIM EXTENDED FUNCTIONAL DESCRIPTOR.

The host learns a device's MBIMEx version through two ways: In this section, the term MBIMEx version refers to the MBIM Extensions release number.

Xcode not downloading