User Guide Part 2

19 7signal solution 104
7signal Solutions, Inc., 526 S. Main Street, Akron, Ohio 44311, USA, 855-763-9526, [e-mail], www.7signal.com
7signal Sapphire Carat User Guide Release 5.0
19 SERVICE LEVEL AGREEMENT
Service Level Agreement (SLA) groups a number of KPIs and their expected target values. In a
nutshell, typically a KPI has a scalar value while SLA is combination of numerous KPI values and
statistical rules that result in a higher-level view on the quality of the network.
The ultimate goal is to bind together a contractual agreement and actual measurements, the
expression of the desired or required level of the service and the proven real-life phenomena.
As such, the SLA is a communication medium between the service provider and the customer.
The SLA outcome is percentage value and based on user-defined thresholds it is divided into
values green, yellow and red according the three-basket principle. This means that the end-
user experience on the WLAN network might remain adequate but the resulting SLA value is
clearly in the red basket.
Related icons
SLA template SLA KPI definition
SLA group KPI definition
19.1 Defining a Service Level Agreement into the system
A network service provider can make Service Level Agreements (SLA) with their customers,
defining the level of service provided to the customer. 7signal Sapphire enables users to
monitor the fulfillment of the various performance level guarantees defined in the SLA.
The user may freely choose the performance indicators to be monitored in the
service level agreement, in effect forming out of them an SLA group.
19.2 Defining SLA Key Performance Indicators (KPI)
In 7signal Sapphire an SLA group is formed out of a set of Key Performance Indicators
corresponding to the SLA. The SLA group is bound to a topology element in the monitored
network. If an SLA group is not bound to a topology element, 7signal Sapphire applies the
default SLA group, or if not defined, the SLA limits defined for KPIs in the SLA template.
An SLA group consists of several KPIs which define the boundary values used in monitoring the
fulfillment of the service level agreement.
In the 7signal Sapphire system the boundary values can be set separately for each KPI
contained in the SLA group. Each KPI defines a certain type of boundary value and percentage
values for how many measurement samples may fall outside the defined boundary values
without causing the service level agreement to be considered unfulfilled. The type of the KPI
determines whether measurement samples with values over or under the boundary value are
desired.
Three color coding is used for service levels in the KPIs: green, yellow and red. The percentage
boundaries are defined for green and yellow levels of service.
To attain the green level of service the percentage of measurement samples that fulfill the
boundary value criteria set in the KPI (that is, are over or under the set boundary value,
depending on the type of KPI) must be at least as high as the percentage boundary value set
for the green level in the KPI. If there are too many measurement samples that do not fulfill