The underlying philosophy behind the Meta-QoS-Class concept introduced by MESCAL project relies on a worldwide common understanding of application QoS needs. MESCAL believes that wherever end-users are connected they more or less use the same kinds of applications in quite similar business contexts. MESCAL believes also that customers experience the same QoS difficulties and are likely to express very similar QoS requirements to their respective providers. In MESCAL terminology, this is denoted by "Customer God". Globally confronted with the same customers' requirements, MESCAL has concluded that providers are likely to define and deploy similar l-QCs, each of them being particularly designed to support applications requiring the same kind of QoS constraints.

Meta-QoS-Class should not be confused with DiffServ PDB (Per Domain Behaviour) notion. The two notions share the common characteristic of specifying some QoS performance values. The two concepts differ in their purposes. The objective for the definition of a PDB is to help implementation of local QoS classes within a single administrative domain. The objective for Meta-QoS-Class is to help agreement negotiation between providers. A Meta-QoS-Class typically bears properties relevant to the crossing of one and only one domain. However this notion can be extended to the crossing of several domains, as long as the set of consecutive domains is considered as a single virtual domain.

MESCAL believes that each provider must have the same understanding of what a given meta-QoS-Class is about. Therefore, a global agreement on a set of Meta-QoS-Class standards is needed. MESCAL recommends that the number of classes to be defined must remain very small to avoid an overwhelming complexity and that there is a need for standardization of Meta-QoS-Classes.

Further reading:

P. Levis, M. Boucadair, P. Morand, P.Trimintzios, "The Meta-QoS-Class concept: a step towards global QoS inter-domain services", Proc. IEEE Int. Conference on Software, Telecommunications and Computer Networks (SoftCOM 2004), October 2004. [pdf document]

P. Levis, M. Boucadair (Eds.), "The Meta-QoS-Class concept", draft-levis-meta-qos-class-00.txt, Work in Progress, June 2005. [link]

MESCAL deliverable D1.3, "Final specification of protocols and algorithms for inter-domain SLS management and traffic engineering for QoS-based IP service delivery", Chapter 4, section 4.2.3. [link]