(1) request: the client sends a request to the master node.
(2) pre-prepared: The master node receives the request from the client and needs to verify whether the signature of the client request message is correct. If correct, a pre-prepare message is broadcast to other replica nodes.
(3) prepared: the replica node receives the pre-prepare message from the master node and carries out verification. If correct, the replica node sends a prepare message to other nodes, including the primary.
(4) committed: the master node and the replica node receive the prepare message and carry out the verification. If the replica node receives a 2f + 1 verified prepare message indicating that most nodes in the network have received the consent message, a commit message is sent to other nodes, including the primary.
(5) reply: the master node and the replica node receive the commit message. If the replica node receives 2f + 1 verified commit messages, it indicates that most nodes in the current network have reached a consensus.
If the master node drops calls or does not broadcast the client request, the client sets a timeout mechanism that broad- casts the request message to all replica nodes. The replica node detects that the master node has committed a crime or is offline and initiates the view rotation protocol. View change: the node receives 2f + 1 view change messages with the same block number.