pynetdicom.pdu.A_ASSOCIATE_AC¶

class pynetdicom.pdu.A_ASSOCIATE_AC(primitive: Optional[A_ASSOCIATE] = None)[source]¶

An A-ASSOCIATE-AC PDU.

An A-ASSOCIATE-AC PDU is sent by an association acceptor to indicate that association negotiation has been successful.

pdu_type¶

The PDU Type field value (0x02).

Type: int

protocol_version¶

The Protocol Version field value (default 0x01).

Type: int

variable_items¶

A list containing the A-ASSOCIATE-AC’s ‘Variable Items’. Contains one Application Context item, one or more Presentation Context items and one User Information item. The order of the items is not guaranteed.

Type: list

Notes

An A-ASSOCIATE-AC PDU requires the following parameters:

PDU type (1, fixed value, 0x02)
PDU length (1)
Protocol version (1, default value, 0x01)
Variable items (1)
- Application Context Item (1)
  - Item type (1, fixed value, 0x10)
  - Item length (1)
  - Application Context Name (1, fixed in an application)
- Presentation Context Item(s) (1 or more)
  - Item type (1, fixed value, 0x21)
  - Item length (1)
  - Context ID (1)
  - Result/reason (1)
  - Transfer Syntax Sub-items (1)
    - Item type (1, fixed, 0x40)
    - Item length (1)
    - Transfer syntax name(s) (1)
- User Information Item (1)
  - Item type (1, fixed, 0x50)
  - Item length (1)
  - User data Sub-items (2 or more)
    Maximum Length Received Sub-item (1)
    
    Implementation Class UID Sub-item (1)
    
    Optional User Data Sub-items (0 or more)

Encoding

When encoded, an A-ASSOCIATE-AC PDU has the following structure, taken from Table 9-17 (offsets shown with Python indexing). PDUs are always encoded using Big Endian.

Offset	Length	Description
0	1	PDU type
1	1	Reserved
2	4	PDU length
6	2	Protocol version
8	2	Reserved
10	16	Reserved^
26	16	Reserved^
42	32	Reserved
74	Variable	Variable items

^ The reserved fields shall be sent with a value identical to the value received in the A-ASSOCIATE-RQ but their values shall not be tested.

References

DICOM Standard, Part 8, Section 9.3.3
DICOM Standard, Part 8, Section 9.3.1

__init__(primitive: Optional[A_ASSOCIATE] = None) → None[source]¶

Initialise a new A-ASSOCIATE-AC PDU.

Parameters: primitive (pynetdicom.pdu_primitive.A_ASSOCIATE) – The primitive to use to initialise the PDU.

Methods

`__init__`([primitive])	Initialise a new A-ASSOCIATE-AC PDU.
`decode`(bytestream)	Decode bytestream and use the result to set the field values of the PDU.
`encode`()	Return the encoded PDU as `bytes`.
`from_primitive`(primitive)	Setup the current PDU using an A-ASSOCIATE (accept) primitive.
`to_primitive`()	Return an A-ASSOCIATE (accept) primitive from the current PDU.

Attributes

`application_context_name`	Return the Application Context Name, if available.
`called_ae_title`	Return the value sent in the Called AE Title reserved space.
`calling_ae_title`	Return the value sent in the Calling AE Title reserved space.
`pdu_length`	Return the PDU Length field value as an int.
`pdu_type`	Return the PDU Type field value as `int`.
`presentation_context`	Return a list of the Presentation Context Items.
`reserved_aec`	Get or set the A-ASSOCIATE-AC's reserved Calling AE Title value.
`reserved_aet`	Get or set the A-ASSOCIATE-AC's reserved Called AE Title value.
`user_information`	Return the User Information Item, if available.

property application_context_name: Optional[UID]¶

Return the Application Context Name, if available.

Returns: The acceptor’s Application Context Name or None if not available.
Return type: pydicom.uid.UID or None

property called_ae_title: str¶

Return the value sent in the Called AE Title reserved space.

While the standard says this value should match the A-ASSOCIATE-RQ value there is no guarantee and this should not be used as a check value.

Returns: The value the A-ASSOCIATE-AC sent in the Called AE Title reserved space. May be an empty string if unable to decode the value.
Return type: str

property calling_ae_title: str¶

Return the value sent in the Calling AE Title reserved space.

While the standard says this value should match the A-ASSOCIATE-RQ value there is no guarantee and this should not be used as a check value.

Returns: The value the A-ASSOCIATE-AC sent in the Calling AE Title reserved space. May be an empty string if unable to decode the value.
Return type: bytes

from_primitive(primitive: A_ASSOCIATE) → None[source]¶

Setup the current PDU using an A-ASSOCIATE (accept) primitive.

Parameters: primitive (pdu_primitives.A_ASSOCIATE) – The primitive to use to set the current PDU field values.

property pdu_length: int¶: Return the PDU Length field value as an int.

property presentation_context: List[PresentationContextItemAC]¶

Return a list of the Presentation Context Items.

Returns: The Presentation Context Items.
Return type: list of pdu_items.PresentationContextItemAC

property reserved_aec: str¶

Get or set the A-ASSOCIATE-AC’s reserved Calling AE Title value.

Parameters: value (str or bytes) – The value at offset 27-42 in the A-ASSOCIATE-AC PDU, usually the same value as the Calling AE Title.
Returns: The decoded value at offset 27-42 in the A-ASSOCIATE-AC PDU, usually the same value as the Calling AE Title, or '' if unable to decode the value.
Return type: str

property reserved_aet: str¶

Get or set the A-ASSOCIATE-AC’s reserved Called AE Title value.

Parameters: value (str or bytes) – The value at offset 11-26 in the A-ASSOCIATE-AC PDU, usually the same value as the Called AE Title.
Returns: The decoded value at offset 11-26 in the A-ASSOCIATE-AC PDU, usually the same value as the Called AE Title, or '' if unable to decode the value.
Return type: str

to_primitive() → A_ASSOCIATE[source]¶

Return an A-ASSOCIATE (accept) primitive from the current PDU.

Returns: The primitive representation of the current PDU.
Return type: pdu_primitives.A_ASSOCIATE

property user_information: Optional[UserInformationItem]¶

Return the User Information Item, if available.

Returns: The acceptor’s User Information object or None, if not available.
Return type: pdu_items.UserInformationItem or None