Service Level Management: From Quality of Device to Quality of Service

    Gabi Dreo Rodosek, University of Federal Armed Forces Munich

By moving from device-oriented to service-oriented management we have
to face several new challenges. Some of the challenges refer to the
formalization of Service Level Agreements (SLAs) and the question how
to obtain the so-called Quality of Service (QoS) parameters such as
availability out of Quality of Device (QoD) parameters such as
IfOperStatus.

The formalization of SLAs is still an open issue. An approach is to
formalize SLAs based upon WS-Agreement specifications that allow the
specification of service functionalities as well as adequate QoS
parameters to quantify the service quality. However, open issues refer
to the questions what are the elements of a SLA as well as what are
the relevant QoS parameters for specific services. A generic approach
is still missing.

When dealing with QoS parameters the challenge is to provide customer-
and service-oriented parameters such as response time if accessing a
web site instead of device-oriented parameters such as InOctets. The
challenge is to provide "what a customer wants to see" and not "what a
provider can provide wrt. management tools and techniques". Thus, this
gap can be filled by approaching from a top-down (e.g., the vision) or
a bottom-up (e.g., state of the art) perspective. Issues like what are
the basic data, the appropriate metrics, the relevant QoS parameters,
the various reporting groups (e.g., managers, operational stuff,
customers) as well as the measurement approaches need to be addressed.