0006034: Subscription publish Min 02 - retransmission queue - MantisBT

ID	Project	Category	View Status	Date Submitted	Last Update

0006034	Compliance Test Tool (CTT) Unified Architecture	Api Change	public	2020-09-17 15:17	2020-10-02 15:22

Reporter	Jim Luth	Assigned To	Alexander Allmendinger
Priority	normal	Severity	minor	Reproducibility	always
Status	assigned	Resolution	open
Product Version	1.04

Summary	0006034: Subscription publish Min 02 - retransmission queue
Description	States that support for a retransmission queue is not required, but this statement does not provided enough details on how the server should function with regard to acknowledgement of sequence numbers. This cause interoperability issue with regards to clients that send an ack for the received sequence number. The specification say to return an error is the sequencenumber is not in the list. This conformance unit should either: 1) not allow a 0 size, but at least have a size of 1 (i.e. the message that just went out (which will allow clients to ack it) [preferred] 2) add text about behavior with regard to client ack of the sequence number - i.e. all number passed if no queue is present are always just accepted (no Bad_SequenceNumberUnknown is returned - just a good) - review all other specification section since multiple other location in the spec describe that a retransmission queue is required and describe behavior related to it. - this may require updates more updates in other parts also.
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Files Affected

Jim Luth 2020-09-17 15:17 administrator ~0012915	Add return code: Good-RetransmissionQueueNotSupported to be returned in the Publish. Possibly add a ServerCapabilities to indicate support for Retransmission (Part 5).

Matthias Damm 2020-09-17 15:17 reporter ~0012916	5.13 Subscription Service Set 5.13.1.1 Description Replace i) with the following text: Sessions maintain a retransmission queue of sent NotificationMessages. NotificationMessages are retained in this queue until they are acknowledged. The Session shall maintain a retransmission queue size of at least two times the number of Publish requests per Session the Server supports. A Profile in OPC 10000-7 may make the retransmission queue support optional. The minimum number of Publish requests per Session the Server shall support is defined in OPC 10000-7. Clients are required to acknowledge NotificationMessages as they are received if the Publish response parameter availableSquenceNumber is not an empty array. An empty array in availableSquenceNumber indicates that the Server does not support a retransmission queue and acknowledgemet of NotificationMessages. In the case of a retransmission queue overflow, the oldest sent NotificationMessage gets deleted. If a Subscription is transferred to another Session, the queued NotificationMessages for this Subscription are moved from the old to the new Session. 5.13.5 Publish Table 95 – Publish Service Parameters Replace availableSequenceNumbers description with the following text: A list of sequence number ranges that identify unacknowledged NotificationMessages that are available for retransmission from the Subscription’s retransmission queue including the sequence number of this response if it is not a keep-alive Message. This list is prepared after processing the acknowledgements in the request (see 7.8 for Counter definition). The list shall be empty if the Server does not support the retransmission queue. If the list is empty, the Client should not acknowledge sequence numbers. Table 97 – Publish Operation Level Result Codes Add status code to table Good_RetransmissionQueueNotSupported The Server does not support retransmission queue and acknowledgement of sequence numbers is not available. Updated in OPC 10000-4 - UA Specification Part 4 - Services 1.05.0 Draft11.docx Errata is prepared

Date Modified	Username	Field	Change
2020-09-17 15:17	Jim Luth	New Issue
2020-09-17 15:17	Jim Luth	Issue generated from: 0005634
2020-09-17 15:17	Jim Luth	Note Added: 0012915
2020-09-17 15:17	Jim Luth	Note Added: 0012916
2020-09-17 15:17	Jim Luth	Relationship added	related to 0005634
2020-09-17 15:18	Jim Luth	Project	10000-004: Services => Compliance Test Tool (CTT) Unified Architecture
2020-09-17 15:18	Jim Luth	Category	Spec => Api Change
2020-10-02 15:20	Paul Hunkar	Assigned To	=> Alexander Allmendinger
2020-10-02 15:20	Paul Hunkar	Status	new => assigned
2020-10-02 15:22	Paul Hunkar	Relationship added	related to 0006089