A service level agreement( SLA) is a bilateral, legal quality of service agreement between network provider and customer, in which the contractual agreements on the quality of services are specified. The essential aspects of such a quality agreement, in which the network and service parameters are specified, include bandwidth, availability, response time, network capacity and network quality.
In addition to the technical parameters mentioned above, the quality of service, the technology and measurement techniques used to provide the services, availability, downtime, response time and repair time, factors affecting the quality of service, also play a role.
A quality of service agreement covers all services, networks, components and connections: Voice services, data services and Internet services, basic services and value-added services, fixed networks and mobile networks, local networks, city networks and wide area networks, as well as fixed links, microwave links and end-to-end links. Since there are no standards for quality of service agreements, any service provider can label any offerings and services with the SLA label.
An SLA agreement should define the subject of the service, include the duration and termination terms, describe the technical performance, cover the handling of faults, contractual penalties and change management.
Newer approaches go far beyond IT-specific agreements and also place requirements on the company's business processes in the SLAs. For example, the number of transactions processed, the print output or the quantity of archived documents. Additional administrative, personnel, development, production, marketing and sales parameters can be included in these approaches.