WS-Management > Support for WS-Management in Intel AMT > DSP0226: Web Services for Management (WS-Management) Specification

DSP0226: Web Services for Management (WS-Management) Specification

Intel AMT Release 3.2 and later releases support the following WS-Management specification:

DMTF Web Services for Management (DSP0226) 1.0.0, February 12, 2008

The following paragraphs detail aspects of Intel AMT compliance to DSP0226.

Section 6: WS-Management Control Headers

   Operation Timeout

Most management operations are time-critical due to quality-of-service constraints and obligations. The WS-Management protocol defines an optional <wsman:OperationTimeout> tag in the SOAP header which specifies the client's request to complete the operation within the specified timeout. Since Intel AMT cannot estimate the time to complete an operation, the implementation enforces a minimum timeout of 30 seconds, which should be sufficient to complete any operation that Intel AMT supports. Clients should be flexible enough in handling related WS-Management faults that occur for operations that might take longer than 30 seconds.

   Envelope Size

The WS-Management protocol defines an optional <wsman:MaxEnvelopeSize> tag in the SOAP header which specifies the client's request to limit the length of the response size. Intel AMT Release 3.0 requires that if clients specify a maximum response size limitation, then the value for the tag must be at least 50000. If a client specifies a lower value, then it might receive a corresponding WS-Management fault according to the WS-Management specification.

   OptionSet Support

Intel AMT does not support the WS-Management Options. If the WS-Management Header OptionSet element is passed with a MustUnderstand=true, Intel AMTwill return a soap:MustUnderstand fault.

Section 7: Resource Access

Intel AMT supports WS-Transfer Get, Put, Delete and Create operations. It does not support fragment level operations.

   Key/Required Field Usage in WS-Management Operations

When invoking intrinsic WS-Management operations (Get, Put, Create), the CIM object representation must include all Key/Required properties of the instance, as defined in the CIM-XML mapping standard. Similarly, any methods receiving or returning Required fields must receive or return these fields.

If a client attempts to invoke a method and fails to pass a Key or Required element, Intel AMT returns a wsman:SchemaValidationError fault.

In some cases, Intel AMT expects certain fields, although they are not denoted as Required or Key in the MOF file. If a property that the Intel AMT device requires for an operation is not passed, Intel AMT returns an wxf:InvalidRepresentation fault on a Put or Create; other methods return a wsman:InvalidParameter fault.

 Note:

Consult the description of each CIM class to determine which properties are key/required.

 

   Using Create and Put with Read-Only Properties

When using the Create and Put operations, according to the previously-defined rules for Key and Required properties, all Key or Required properties must be passed. Notice that not all fields of a class are writable; for example, the CreationClassName property is never writable in Intel AMT.

Properties which are read-only and are passed in the Create or Put operations will be ignored, and Intel AMT will fill its own value for them. Any schema-compliant value may be passed for these properties.

Specifically, this means the client must pass all keys, whether they are read-only or writable; read-only keys will be ignored, but must nevertheless be passed.

   Using Create and Put with Write-Only Properties

Some properties are treated by the implementation as write only (this is an implementation specific behavior that is not modeled in CIM). Such a property can be updated in Create or Put but cannot be read via Get. For example, passwords are write-only properties.

   Return Value from Put Operations

In Releases 3.0 through 5.0, Intel AMT does not return the representation of an object after a Put operation. The client should invoke another Get request to get the new representation. However, if the Put request includes a read/write property, and the Intel AMT device does not return a fault, the client can assume that the value of any changed fields has been updated to the requested value.

Starting with Release 5.1, Put operations do return the updated representation of the object.

Section 8: WS-Enumeration

Intel AMT provides a mechanism for enumerating a multi-instanced resource or querying the set of instances using WS-Enumeration.

The WS-Enumeration specification indicates that enumeration is a three-part operation: An initial wsen:Enumerate is issued to establish the enumeration context and wsen:Pull operations are used to iterate over the result set. When the enumeration iterator is no longer required and not yet exhausted, a wsen:Release is issued to release the enumerator and associated resources.

Intel AMT allocates a resource which is reserved for the client during the enumeration period. The implementation imposes the following restrictions to the enumeration operation:

   The enumeration flow (enumerate, pull, release) should be completed within 30 seconds. If 30 seconds pass before the flow completes, the enumeration context may be purged for the use of other clients requesting to enumerate a resource.

   When the client pulls the last resource, the enumeration context will be purged.

   Clients should not rely on the timeout purge mechanism. Rather, they should release the enumeration context as soon as they obtain the data they need.

   Intel AMT supports multiple concurrent enumeration flows. If all of the enumeration contexts are consumed, Intel AMT returns a concurrency fault:
"The action could not be completed due to concurrency or locking problems."

   An enumeration filter can define an “associated” or “association” context. An association context returns those objects that associate a specified instance to other instances. An associated context retrieves instances (of various classes) that are associated with a specified instance.

In Intel AMT releases before 7.0, only one of the three enumeration flows at a time can support an “associated” context. That flow will lock out other “associated” filters either until the context is released or until the context times out.

Release

Number of Supported Concurrent Enumeration Flows

Total Number of Concurrent Enumeration Contexts

Pre-7.0

3

1

7.0

3

3

8.0

6

3

 

 Note:

   In pre-8.0 releases, Intel AMT supports three concurrent enumeration flows. Starting with Release 7.0, all three of the enumeration flows can support an "association" context.

   Starting in Release 8.0, Intel AMT supports six concurrent enumeration flows.  Within those six concurrent flows, only three flows can support an “association” context.

   The number of contexts is subject to change (to be increased or decreased) in future releases, so an implementation should not depend on specific values.

   Note that more than one application may be consuming these resources simultaneously so a single application cannot depend on having all of them available.

 

Section 12: Security

Intel AMT supports the following security profiles:

   http://schemas.dmtf.org/wbem/wsman/1/wsman/secprofile/http/digest

   http://schemas.dmtf.org/wbem/wsman/1/wsman/secprofile/https/digest

   http://schemas.dmtf.org/wbem/wsman/1/wsman/secprofile/https/mutual/ digest

   http://schemas.dmtf.org/wbem/wsman/1/wsman/secprofile/https/ spnego-kerberos

   http://schemas.dmtf.org/wbem/wsman/1/wsman/secprofile/https/mutual/ spnego-kerberos

Section 13: Transports and Message Encoding

   UTF Encoding

Intel AMT supports UTF-8 only (as UTF-16 is no longer mandatory according to WIP WSMANCR00041.001)

   Whitespace in XML Elements Policy

Intel AMT treats any information within a simple XML element tag as the tag’s value. Numeric fields may contain whitespaces; string and string-based elements containing any whitespace, including heading or trailing whitespaces, will be treated as though the whitespaces are part of the field’s value.

Section 14: Faults

The following sections describe how Intel AMT maps WBEM intrinsic and extrinsic failures into SOAP-Faults.

The first section discusses the mapping. The second section lists the error codes. The final section provides a description of each code.

See Also:

   Errors and Return Values

   Intel AMT Returned Numeric Values (PT_STATUS codes)

   Description of PT_STATUS Responses

 

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