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] |