All, As I mentioned on the call last week, I think we need another NSI protocol requirement as following: The provider agent involved in the /initial /NSI request from an NSI requesting agent (in these cases, the requester agent acts as an /end user or application/), must take on the responsibility of replying back to the end user the result of the request. That is either a failure or success with the correct pointers or Global Identifiers. This needs to be true regardless of weather the initial provider agent uses chain or tree model to reserve a path. This requirement will have implications on the intermediate messaging that take place between the requesting agents and provider agents along the path. I can also imagine that the messaging to uphold this requirement will be different for tree vs chain. I hope this makes sense... Kind regards, Gigi