Consider the following scenario that takes Microsoft Exchange Server 2013 as an example:
- The Mailbox server role is enabled in Exchange Server 2013.
- Exchange mailboxes use extended MAPI to communicate with the Exchange Server.
- The extended MAPI uses Microsoft RPC over HTTP (remote procedure call over HTTP) protocol.
- Many clients (such as mobile devices) are dropping connections to the Exchange Server.
In this scenario, the CPU usage on the Exchange server may reach 100 percent.\