A Service Level Agreement is a contract between a network Service Provider and a customer, which defines the terms of types of services, quality of services and the customer payment. A typical SLA includes the following items:

• The minimum bandwidth allocated to the customer
• The burst bandwidth for the customer
• The number of users that can be served simultaneously
• The schedule for notification in advance of network changes that may affect users
• Dial-in access availability
• Usage statistics that will be provided
• The minimum network availability from the service provider, such as 99.9% up time or a maximum of down time of 1 minute per day.
• The priority of the traffic per type of the customer
• Customer technique support and services
• Penalty provisions if the Service Provider does not meet the SLA

To comply with the SLA, Service Providers use many techniques and solutions to monitor and manage network performance and traffic to meet the requirements in the SLA and to generate corresponding reports to show customers the results.

On the other hand, customers come up with their own technologies and solution to monitor the traffic and services from their side to ensure the Service provide delivers what they promised.

The SLA concept has been adopted by many large enterprises for the internal services of the IT department to the rest of the company. The IT departments of large enterprises writes a service level agreement so that services for their customers (users in other departments within the enterprise) can be measured, justified, and perhaps compared with those of outsourcing network providers.

Related Terms: QoS (Quality of Service), Traffic Management, Class of Service (CoS)