[Nsi-wg] Draft NSI Connection Service Protocol document

[John MacAuley]

Peoples,

I think we have a small issue with the existing state machine when being observed externally across the protocol interface.  At the moment, if I send a provisionRequest message to the PA we have a conditional transition based on startTime that is not being modeled.  I remember the long discussions over this, but I think we need to revisit it quickly.

As per section 3.3...

Transition #1: Reserved state -> Provisioning state
Precondition: reservation exists; state machine in reserved state, and current time is past startTime.
provisionRequest: results in a transition from Reserved state into Provisioning state.

Transition #2: Reserved state -> Reserved state
 - Precondition: reservation exists; state machine in reserved state, and current time is before startTime.
 - provisionRequest: results in a transition from Reserved state to Reserved state.

With this state machine definition, and the current interface definition, there is no way to determine the difference between a Reserved state having already received a provisionRequest and a Reserved state having not received a provisionRequest.  I think the distinction is important from an implementation perspective.  In OpenDRAC we have an “Activated” state modeled between the “Reserved” and “Provisioning” which lets us transition into “Provisioning” once the startTime occurs.

I am sorry to open this up again, but I was thinking of implementation and realized I could not get back this unmodeled state in a queryRequest.

Comments?

John.


3.3 Provisioning a Connection
When the Connection is in the Reserved state the RA can send a provisionRequest message.  This request will be treated in two possible ways depending on the arrival of the request in relation to the startTime nominated in the reserveRequest message:
• Where the startTime has already passed (according to the PA local timer), receipt of the provisionRequest message results in the Connection state moving to Provisioning.
• Were the startTime has not yet arrived (according to the PA local timer), the Connection remains in the Reserved state until the startTime is reached.  The Connection state then moves to Provisioning.
When the NRM indicates that the provisioning has been correctly completed, the Connection moves to the In-Service state.  *** What happens if provisioning fails???