[brigadier132]

Exactly once delivery is when a message is delivered to any computer at any layer of abstraction exactly once.

It doesn't matter if TCP abstracts or any other layer abstracts this away, if a message can be delivered more than once it does not have the property of exactly once delivery.

You might disagree with this definition but you would be wrong. There is negative value in redefining exactly once delivery to mean what you think it means.

[lisper]

But I don't disagree with that definition. The only thing in dispute is whether or not it is possible to achieve. It seems clear to me that it is possible, but for some reason that I still don't understand people keep insisting that it isn't.