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Table of Contents

Requirements

#	Interface	Requirement	Additional Information
1	CPS-E-08.e	NCMP is to merge CM Notification Subscriptions Create request for the same CM Handle & XPath(s)	Prevent unnecessary subscription updates to nodes already involved in a subscription to the same path For possible combinations, see table below
2	CPS-E-08.e	Last lights out: upon subscription Delete request only when there is no more subscription for a cm-handle & xpath combination a subscription-delete request wil be send to the relevant DMI(s)
3	CPS-E-08.e	Amalgamation per DMI: all subscription updates originating from a single client request should be send to a single DMI in one request (message). Of course there can be several message if more than 1 DMI is involved.
4	CPS-NCMP-I-01	CM Handle deletion should update subscription details
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#	Error Scenario	Expected behavior	Sign-off
1
2

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CM Notification Forwarding Check: When forwarding CM Notification NCMP will not check the content to see if the is a valid active subscription. It is assumed that the DMI Plugin as acted on the 'delete subscription' request (that request is NCMPs responsibility). And of course there wil be timing issues it also possible a CM Notification was send just after the subscription-delete was send (from client) but before the whole change had acted upon that.
Retry: NCMP wil only report when actions are pending or rejected. NCMP will not implement a retry mechanism
Wildcards: Wildcards or similar functionality where one string represent 0 or more xpaths is not covered as part of this requirement but it should be kept in mind as a future possibility
Dynamic Topic: Topic for CM Notifications back to client remain

#	Assumption	Notes
1	Targets is a collection of xpaths	can be implemented as a json array of strings
2	for the DMI plugin cm-handle-id and xpath are the key to a unique subscription	the client (name) is -id and subscription name are not relevant for the DMI (should not be included in the request) as this would break the concept of merging!

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#	Issue	Notes
1	Is it intended that CM Notification subscription request cover (all) descendants of the given xpath too?!	e.g.. if a child ire removed and there is a subscription for the parent node, will a notification be send (grandchild, child leaf updates etc.) I hope NOT!
2	Could xpath point to an element that does not exist (yet)	if not how, how can I client be informed about a create event?
3	Should NCMP support re-homing, moving of a CM Handle from one DMI to another?
4	CM Handle Delete: Should DMI or Clients be sent a subscription update (assume no)

NCMP treat a Client Subscription as one or more (small) DMI Subscriptions, each of which wil have there own state.
Each DMI Subscription is related to 1 or more client subscription.
If there is no more related client subscription the DMI Subscription can be deleted (once accepted by DMI Plugin)!

	Existing Subscription

1

A	Client Create Subscription

2

CM-1c2 CMc2 CMc2 CMc2 ]

	NCMP Existing A	NCMP Existing B	Client Delete A Request	DMI Delete Request
1	CMCH-1, [ /p/c1, p/c2 ]	CMCH-1, [ /p/c1 ]	CMCH-1, [ /p/c1, p/c2 ]	None	CH-1, [ p/c2 ]
2	CH-1, [ /p/c1] CH-2, [ /p/c1]	CH-2, [ /p/	c1] CH-3, [ /p/c1]	CH-1, [ /p/c1] CH-2, [ /p/	c1]	CH-1, [ /p/c1]
3	CH-1, [ /p/	c1]		CH-1, [ /p/	c1] CH-2, [ /p/c1]	CH-1, [ /p/c1]	None

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