Picking Your ISP – Defining SLA and MTTR

Picking Your ISP – Defining SLA and MTTR

There is a myriad of options when it comes to Internet Service Providers (ISP) making it hard to select one. By having a better understanding of what terminologies such as SLAs and MTTRs mean, you will be in a better position in picking the right ISP for your needs.

What is the SLA?

A Service Level Agreement or SLA is an agreement that has been formally negotiated between two parties. Basically, it is a contract that exists between the service provider and the customer. It is a document of the level of service that is guaranteed by the service provider.

What an SLA does?

An SLA does the following:

  • Sets definitions such as length of timeframe
  • Describes the level of service that will be offered
  • Explains the methods of measurement of performance
  • Defines penalties in case of failure
  • Illustrates how problems about the SLA will be resolved

What is Mean Time To Repair (MTTR)?

Mean Time To Repair or MTTR is the time taken between interruption to restoration of service. It includes diagnosis and repair of problems. If the changes are unmanaged and uncontrolled, problem diagnosis dominates a major part of MTTR. For example, if a company faces outage and the problem managers are trying to find the factors that contributed to the problem, crucial time is lost in calling for meetings, making phone calls, making mistakes in diagnosis, applying the wrong solution, to name a few. The end result is a high MTTR value.

Once the changes are managed and documented, the time taken to investigate the problem decreases. For example, the managers already know the factors that caused the outage due to documentation. They can schedule changes accordingly and fix the problem within a given period of time. This results in a low MTTR value. Also, the problem can be diagnosed correctly, without having to log onto the servers.


From the above to examples, you can see the correlation between uncontrollable change and high MTTR. If there is a decrease in the level of control for each change, MTTR increases and predictability reduces.