|Description of its function
||Functionality is the most important aspect of your design. Your design is functional when it fulfills the basic reason for implementing the networking service.
For example, if a remote access server allows users to connect to private network resources, your remote access design is functional.
||The security aspect of your design ensures the confidentiality of data. Your design is secure when only authorized users are provided access to confidential data.
|| Your design is available to the extent that users have access to the functionality that is provided by the networking service.
You calculate availability by measuring the percentage of time that users have access to the service. The higher the availability, the higher the ratio between uptime and downtime provided by the service.
|| The performance aspect of your design is based on response times specified by the organization's goals.
The performance of a networking service is typically driven by real-world events that must occur within a period of time, such as purchasing a product from an e-commerce Internet site.
|Its relationship to other design aspects
||Functionality is independent of the other categories. Thus your design may be functional but not secure or highly available, or it may not meet performance criteria.
When reviewing a design, you must evaluate the functionality requirements of the design first. If your design is not functional, the remaining design aspects are irrelevant
|| Security is based on the functionality aspects of your design, but it is independent of the availability and performance aspects. Your design may be secure but not highly available, or it may not meet performance criteria.
||Availability is based on the functionality aspects of your design, but it is independent of the security and performance aspects. Your design may be highly available but not secure, or it may not meet performance criteria.
||Performance is based on the functionality aspects of your design, but it is independent of the security and availability aspects. Your design may exceed the performance criteria of the design but not be secure or exhibit high availability.