DICOM Print SCP: Association aborted after successful N-SET/N-GET on Windows 7 32-bit (pynetdicom 2.0.2)

[patildevendra-0]

I am implementing a DICOM Print SCP using pynetdicom.

Environment:

• Windows 7 32-bit
• Python 3.8.9 (32-bit)
• pynetdicom 2.0.2
• pydicom 2.4.4

Workflow:

Association succeeds and the following operations occur:

N-CREATE Film Session
N-CREATE Film Box
N-SET Image Box
N-GET Printer

My SCP returns success (0x0000) for N-SET and N-GET.

However modality aborts the association immediately afterwards.

Relevant log excerpt:

Their Max PDU Receive Size: 65542
Our Max PDU Receive Size: 16382

D: OUTGOING DIMSE MESSAGE
Message Type : N-SET RSP
Status : 0x0000

Then modality aborts:

INCOMING A-ABORT PDU
Abort Source: DUL service-user

Interestingly this works when sending from a 64-bit machine to the same SCP, but fails when both sides are 32-bit.

Is this expected behaviour with pynetdicom on Win7 32-bit, or could there be an issue with PDU negotiation or DIMSE response formatting?

Any guidance would be greatly appreciated.

[scaramallion]

There shouldn't be any difference between 32 and 64-bit OSes... can you post the full (anonymised) debugging log and a minimal code example that reproduces the issue? Have you tried with the most recent release?

[patildevendra-0]

Below are the environments used for testing:

Environment 1
OS: Windows 7 (32-bit)
Python: 3.8
pydicom: 2.4.4
pynetdicom: 2.0.2

Environment 2
OS: Windows 11 (64-bit)
Python: 3.10
pydicom: 3.0.1
pynetdicom: 3.0.4

I used the same SCP code in both environments and performed the following tests.

Scenario 1
SCU running on Windows 11 (64-bit) sending images to the SCP running on Windows 7 (32-bit).
Result: The image is received correctly and the workflow completes successfully.

Scenario 2
SCU running on Windows 7 (32-bit) sending images to the SCP running on Windows 11 (64-bit).
Result: This also works correctly and the workflow completes.

Scenario 3
When both SCU and SCP are running on Windows 7 (32-bit) (either on the same machine or different machines), the issue appears.
The association is established, but then an A-ABORT occurs and the workflow stops. After that, the remaining commands are not received.

For testing I also used DICOM Scope as the SCU and observed the same behavior.

I have attached two debug logs for comparison:

1. Working case (Windows 11 64-bit)
2. Failing case (Windows 7 32-bit where both SCU and SCP are 32-bit)

win7-32bit-log.txt
working_64bit_win-11_log.txt

def start_scp(self, host: str, port: int, ae_title: str, printer: str):
ae = AE(ae_title=ae_title)

    ae.maximum_pdu_size = 65536
    ae.implementation_class_uid = IMPLEMENTATION_UID
    ae.implementation_version_name = "Test"
    
    ae.add_supported_context(Verification)
    ae.add_supported_context(
        BasicGrayscalePrintManagementMeta,
        [ExplicitVRLittleEndian, ImplicitVRLittleEndian]
    )

    handlers = [
        (events.EVT_C_ECHO, handle_n_echo),
        (events.EVT_N_CREATE, handle_n_create),
        (events.EVT_N_ACTION, handle_n_action),
        (events.EVT_N_GET, handle_n_get),
        (events.EVT_N_SET, handle_n_set),
        (events.EVT_N_DELETE, handle_n_delete),
        (events.EVT_N_EVENT_REPORT, handle_n_event_report),
    ]

    scp = ae.start_server(
        (host, port),
        block=False,
        evt_handlers=handlers,
    )