フリー問題

問題文

An engineer must state how the quality of service parameters actually reach the traffic in an InfiniBand fabric. Which chain is correct?

選択肢

1. The management entity computes a bandwidth allocation for every pair of endpoints when it discovers them and programs that allocation into the switches on the path, so the parameters do not have to be carried in the packets at all and no mapping is performed at each hop along the way.
2. The partition key doubles as the quality of service identifier, so the parameters follow from the partition the traffic belongs to, and the switches read it from the same field.
3. The adapters negotiate the parameters directly with each other at connection setup.
4. A service level is carried in the packet, and each switch maps it to a virtual lane that holds the buffering and arbitration parameters.