QOS_TRAFFIC_CLASS structure (qosobjs.h)

Article
02/22/2024

The traffic control object QOS_TRAFFIC_CLASS is used to override the default UserPriority value ascribed to packets that classify the traffic of a given flow.

By default, the UserPriority value of a flow is derived from the ServiceType (see: FLOWSPEC). Therefore, it is often necessary to override the default UserPriority because packets can be tagged in their Layer 2 headers (such as an 802.1p header) to specify their priority to Layer-2 devices. Using QOS_TRAFFIC_CLASS enables application developers to override the default UserPriority setting.

Syntax

typedef struct _QOS_TRAFFIC_CLASS {
  QOS_OBJECT_HDR ObjectHdr;
  ULONG          TrafficClass;
} QOS_TRAFFIC_CLASS, *LPQOS_TRAFFIC_CLASS;

Members

ObjectHdr

The QOS object QOS_OBJECT_HDR. The object type for this traffic control object should be QOS_OBJECT_TRAFFIC_CLASS.

TrafficClass

User priority value of the flow. The valid range is zero through seven. The following settings are chosen (by default) when the QOS_TRAFFIC_CLASS traffic control object is not used.

Note This parameter specifies an 802.1 TrafficClass parameter which has been provided to the host by a layer 2 network in an 802.1 extended RSVP RESV message. If this object is obtained from the network, hosts will stamp the MAC headers of corresponding transmitted packets, with the value in the object. Otherwise, hosts can select a value based on the standard Intserv mapping of ServiceType to 802.1 TrafficClass.

SERVICETYPE_BESTEFFORT (0x00000001)

SERVICETYPE_CONTROLLEDLOAD (0x00000002)

SERVICETYPE_GUARANTEED (0x00000003)

SERVICETYPE_NONCONFORMING (0x00000009)

SERVICETYPE_NETWORK_CONTROL (0x0000000A)

SERVICETYPE_QUALITATIVE (0x0000000D)

Remarks

Traffic Control: The following ServiceType enumeration values are invalid when specifically working with Traffic Control.

SERVICE_NO_TRAFFIC_CONTROL

SERVICE_NO_QOS_SIGNALING

SERVICETYPE_GENERAL_INFORMATION

SERVICETYPE_NETWORK_UNAVAILABLE

SERVICETYPE_NOCHANGE

SERVICETYPE_NOTRAFFIC

Requirements

Requirement	Value
Minimum supported client	Windows 2000 Professional [desktop apps only]
Minimum supported server	Windows 2000 Server [desktop apps only]
Header	qosobjs.h