Explanation
KPIs fall under the "business" aspect of QoS, along with monitoring and measuring of events and business processes. Services, security, and applications are all core components and concepts of the "IT" aspect of QoS.

Explanation/Reference:
Explanation:
IPSec is a protocol for encrypting and authenticating packets during transmission between two parties and can involve any type of device, application, or service. The protocol performs both the authentication and negotiation of security policies between the two parties at the start of the connection and then maintains these policies throughout the lifetime of the connection. TLS operates at the application layer, not the network layer, and is widely used to secure communications between two parties. SSL is similar to TLS but has been deprecated. Although a VPN allows a secure channel for communications into a private network from an outside location, it's not a protocol.

Explanation/Reference:
Explanation:
With multiple tenants within the same hosting environment, any failure to properly classify data may lead to potential exposure to other customers and applications within the same environment.

The best practice is to totally remove any unneeded services and utilities on a system to prevent any chance of compromise or use. If they are just disabled, it is possible for them to be inadvertently started again at any point, or another exploit could be used to start them again. Removing also negates the need to patch and maintain them going forward.