Performance & Fault management are important in supporting an SLA. Performance Monitor determines how the network performs and Fault Management has the task providing detection, diagnostics and resolution of network faults. Essential information collected from these go to form what is known as Service Level Agreement (SLA). An SLA is a metric that describes a level of service sold by a service provider to a customer. Supporting and maintaining SLA’s is known as SLA Management.
The Telecommunication Management Network (TMN) is a framework that defines how management is logically seperated in supporting telecommunications networks. It is a protocol model defined by the ITU-T, broken down into for distinctive areas:-
Element Management Layer (EML), this is at the bottom of the pyramid, responsible to managing individual elements of the network, like error rates, alarms etc
Network Management Level (NML), this has the responsibility for ensuring end-to-end connectivity, network reliability and capacity planning. The NML has complete technology independant visibility of the entire network
Service Management Layer (SML), responsible for the VoIP service provider incase of an ITSP to the customer, it provides the contractual aspects of services provided to customers.
Business Management Layer (BML), is responsible for billing, marketing, analysing trends, quality issues and defining company policies
A Service provider must accomplish three main steps to support an SLA for its customers;
1) Collect VoIP Performance and fault Data
2) filter, aggregate and correlate the collected data
3) present and report the data