問題文
A recommendation has been published about the multicast service model that carries a group without naming a sender. An operator has to work out how far it reaches: whether it touches what runs inside its own domain, and what counts as being between domains for this purpose. What does the recommendation say?
選択肢
- The model has to be taken out of the domain as well as between domains, and what counts as being between domains is a deployment whose routers are run by two or more separate administrations.
- Operators do stay free to keep that model inside their own domains, and what counts as being between domains is a deployment that carries traffic across more than one routing area.
- Operators do stay free to keep that model inside their own domains, and what counts as being between domains is a deployment whose routers are run by two or more separate administrations.
- The model has to be taken out of the domain as well as between domains, and what counts as being between domains is a deployment that carries traffic across more than one routing area.