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Indicating Changes to the Remote NDIS QoS Parameters

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The miniport driver that supports NDIS Quality of Service (QoS) issues an NDIS_STATUS_QOS_REMOTE_PARAMETERS_CHANGE status indication when its remote NDIS QoS parameters are either received from a peer for the first time or change later. The miniport driver receives these QoS parameters from a remote peer through the IEEE 802.1Qaz Data Center Bridging Exchange (DCBX) protocol.

The miniport driver must follow these guidelines for issuing an NDIS_STATUS_QOS_REMOTE_PARAMETERS_CHANGE status indication:

  • If the miniport driver has not received a DCBX frame from a remote peer, it must not issue an NDIS_STATUS_QOS_REMOTE_PARAMETERS_CHANGE status indication.

  • The miniport driver must issue an NDIS_STATUS_QOS_REMOTE_PARAMETERS_CHANGE status indication after it has first received the QoS settings from a remote peer.

    Note The miniport driver must issue this status indication if the network adapter receives remote QoS parameter settings from a peer before the driver's local QoS parameters are set. For more information, see Setting Local NDIS QoS Parameters.

  • After this initial status indication, the miniport driver should only issue an NDIS_STATUS_QOS_REMOTE_PARAMETERS_CHANGE status indication when it determines a change in the QoS settings on the remote peer.

    Note Miniport drivers should not issue an NDIS_STATUS_QOS_REMOTE_PARAMETERS_CHANGE status indication if there have been no changes to the remote NDIS QoS parameters. If the driver does make this type of status indication, NDIS may not pass the indication to overlying drivers.

Note The miniport driver must issue NDIS_STATUS_QOS_REMOTE_PARAMETERS_CHANGE status indications if its NDIS QoS capabilities are currently enabled. Starting with Windows Server 2012, these indications allow system administrators to view NDIS QoS and Data Center Bridging (DCB) settings regardless of whether the Microsoft DCB server feature is installed.

Guidelines for Issuing the NDIS_STATUS_QOS_REMOTE_PARAMETERS_CHANGE Status Indication

The miniport driver follows these steps when it issues the NDIS_STATUS_QOS_REMOTE_PARAMETERS_CHANGE status indication:

  1. The miniport driver allocates a buffer that is large enough to contain the following:

    • An NDIS_QOS_PARAMETERS structure that contains the NDIS QoS configuration settings as well as global operational parameters for the NDIS QoS traffic classes.

    • An array of NDIS_QOS_CLASSIFICATION_ELEMENT structures. Each of these structures specifies a traffic classification as defined by a packet data pattern (condition) and associated IEEE 802.1p priority level (action). If the network adapter finds a pattern in the transmit, or egress, packet that matches a condition, it assigns the associated priority level to the packet. The adapter also applies the other NDIS QoS policies to the packet based on the priority level.

  2. The miniport initializes the NDIS_QOS_PARAMETERS structure with the remote NDIS QoS parameters. The driver must provide the complete set of remote parameters that were received from the DCBX frame sent by the remote peer.

    When the miniport driver initializes the Header member, it sets the Type member of Header to NDIS_OBJECT_TYPE_QOS_PARAMETERS. The miniport driver sets the Revision member of Header to NDIS_QOS_PARAMETERS_REVISION_1 and the Size member to NDIS_SIZEOF_QOS_PARAMETERS_REVISION_1.

    The miniport driver sets the appropriate NDIS_QOS_PARAMETERS_Xxx_CHANGED flags if the corresponding members contain data that has changed since the miniport driver previously issued an NDIS_STATUS_QOS_REMOTE_PARAMETERS_CHANGE status indication.

    Note Setting these NDIS_QOS_PARAMETERS_Xxx_CHANGED flags is optional. NDIS always assumes that the members of the NDIS_QOS_PARAMETERS are specified even if they have not changed from the previous NDIS_STATUS_QOS_REMOTE_PARAMETERS_CHANGE status indication.

    The miniport driver sets the Flags member to specify status information for the data that is contained in the NDIS_QOS_PARAMETERS structure members.

    For example, the miniport driver sets the appropriate NDIS_QOS_PARAMETERS_Xxx_CHANGED flags in the Flags member for those members which contain data that has changed since the miniport driver previously issued an NDIS_STATUS_QOS_REMOTE_PARAMETERS_CHANGE status indication.

    For more information on how to set the Flags member, see Guidelines for Setting the Flags Member.

  3. The miniport driver initializes an NDIS_QOS_CLASSIFICATION_ELEMENT structure for each traffic classification from the remote NDIS QoS parameters. The driver adds these elements past the end of the NDIS_QOS_PARAMETERS structure in the buffer.

    Note The miniport driver must not set the NDIS_QOS_CLASSIFICATION_ENFORCED_BY_MINIPORT flag in the Flags member of any NDIS_QOS_CLASSIFICATION_ELEMENT structures.

    The driver sets the NumClassificationElements member of the NDIS_QOS_PARAMETERS structure to the number of classification elements in the array. The driver sets the FirstClassificationElementOffset member to the byte offset of the first element from the start of the buffer. The driver also sets the ClassificationElementSize member to the length, in bytes, of each element in the array.

    Note Starting with NDIS 6.30, the miniport driver must set the ClassificationElementSize member to sizeof(NDIS_QOS_CLASSIFICATION_ELEMENT).

  4. The miniport driver initializes an NDIS_STATUS_INDICATION structure for the status indication in the following way:

    • The StatusCode member must be set to NDIS_STATUS_QOS_REMOTE_PARAMETERS_CHANGE.

    • The StatusBuffer member must be set to the pointer to the buffer that contains the remote NDIS QoS parameters.

    • The StatusBufferSize member must be set to the length, in bytes, of the buffer.

  5. The miniport driver issues the status indication by calling NdisMIndicateStatusEx. The driver must pass a pointer to the NDIS_STATUS_INDICATION structure to the StatusIndication parameter.

Guidelines for Setting the Flags Member

The miniport driver sets the following flags in the Flags member of the NDIS_QOS_PARAMETERS structure to specify which operational NDIS QoS parameters have been configured or changed on the network adapter:

NDIS_QOS_PARAMETERS_ETS_CONFIGURED
If this flag is set, the miniport driver has configured the network adapter with the ETS parameters contained in the following members:

  • NumTrafficClasses

  • PriorityAssignmentTable

  • TcBandwidthAssignmentTable

  • TsaAssignmentTable

Note The miniport driver must support ETS in order to support NDIS QoS for DCB. However, the setting of this flag does not specify whether the network adapter supports ETS. Instead, the setting of this flag specifies only whether ETS parameters are configured on the network adapter.

NDIS_QOS_PARAMETERS_ETS_CHANGED
If this flag is set, one or more ETS parameters have changed in the following members:

  • NumTrafficClasses

  • PriorityAssignmentTable

  • TcBandwidthAssignmentTable

  • TsaAssignmentTable

NDIS_QOS_PARAMETERS_PFC_CONFIGURED
If this flag is set, the miniport driver has configured the network adapter with the PFC settings contained in the PfcEnable member.

Note The miniport driver must support PFC in order to support NDIS QoS for DCB. The setting of this flag does not specify whether the network adapter supports PFC. Instead, the setting of this flag specifies only whether PFC parameters are enabled on the network adapter.

NDIS_QOS_PARAMETERS_PFC_CHANGED
If this flag is set, one or more PFC settings have changed in the PfcEnable member.

NDIS_QOS_PARAMETERS_CLASSIFICATION_CONFIGURED
If this flag is set, the miniport driver has configured the network adapter with the QoS traffic classifications parameters specified in the following members:

  • NumClassificationElements

  • ClassificationElementSize

  • FirstClassificationElementOffset

NDIS_QOS_PARAMETERS_CLASSIFICATION_CHANGED
If this flag is set, one or more QoS traffic classification parameters have changed in the following members:

  • NumClassificationElements

  • ClassificationElementSize

  • FirstClassificationElementOffset

Note The NDIS_QOS_PARAMETERS_Xxx_CONFIGURED flags must be set if the NDIS_QOS_PARAMETERS structure contains NDIS QoS parameter settings. The miniport driver must set these flags regardless of whether the settings have changed. However, the driver must only set the NDIS_QOS_PARAMETERS_Xxx_CHANGED flags for those settings that have changed.

Guidelines for Indicating Invalid Remote NDIS QoS Parameters

The miniport driver must invalidate its remote QoS parameters if the following conditions are true:

  • The time-to-live (TTL) value expires for the remote QoS parameters.

    Note DCBX is carried over the Link Layer Discovery Protocol (LLDP) protocol as specified in the IEEE 802.1AB-2005 standard. LLDP frames always contain a TTL field.

  • Another data-link peer sends a DCBX frame before the TTL value expires. This scenario is known as a multi-peer condition. DCBX requires that the miniport driver maintain only one set of remote QoS parameters that were received from a single data-link peer.

    When a multi-peer condition occurs, the miniport driver must invalidate all of the remote QoS parameters until the TTL value expires for all of the received DCBX frames.

When the miniport driver invalidates its remote NDIS QoS parameters, it must follow these steps when it issues the NDIS_STATUS_QOS_REMOTE_PARAMETERS_CHANGE status indication:

  1. Because the miniport driver is not reporting any valid remote NDIS QoS parameters, it must first fill an NDIS_QOS_PARAMETERS structure with zeros.

    When the miniport driver initializes the Header member of this structure, it sets the Type member of Header to NDIS_OBJECT_TYPE_QOS_PARAMETERS. The miniport driver sets the Revision member of Header to NDIS_QOS_PARAMETERS_REVISION_1 and the Size member to NDIS_SIZEOF_QOS_PARAMETERS_REVISION_1.

    The miniport driver sets the appropriate NDIS_QOS_PARAMETERS_Xxx_CHANGED flags in the Flags member.

  2. The miniport driver initializes an NDIS_STATUS_INDICATION structure for the status indication in the following way:

    • The StatusCode member must be set to NDIS_STATUS_QOS_REMOTE_PARAMETERS_CHANGE.

    • The StatusBuffer member must be set to the address of the NDIS_QOS_PARAMETERS structure.

    • The StatusBufferSize member must be set to sizeof(NDIS_QOS_PARAMETERS).

  3. The miniport driver issues the status indication by calling NdisMIndicateStatusEx. The driver must pass a pointer to the NDIS_STATUS_INDICATION structure to the StatusIndication parameter.