The
MESCAL Internet QoS-based service model lays down the concepts,
notions and relationships between them, pertinent to definition
and provisioning of QoS-based services in the Internet, across multiple
provider domains. In other words, the MESCAL service model presents
the informational architecture, the basic 'service vocabulary',
for building/defining QoS-based services in the Internet. From another
angle, the MESCAL service model outlines the requirements of Internet
QoS-based services from an informational viewpoint. It sets the
functional targets of the service offering and provisioning functionality,
while it also presents the necessary abstractions in the service
layer around which this functionality needs to be designed. The
MESCAL model extends the TEQUILA model of QoS-based intra-domain
services to cover QoS-based services spanning the whole Internet,
rather than the domain of a particular provider.
Specifically, the model specifies the notions of and relations between
QoS-based services, QoS guarantees and c/pSLSes, outlining also
different styles in requesting and establishing c/pSLSes. It then
introduces the concept of QoS Class (QC), the nucleus of QoS-based
services, and specifies the notions of local and external QoS classes
(l-QCs, e-QCs). Different types of QCs are defined depending on
how they can obtain their values and the span of their meaning,
introducing the concepts of meta- and global-QoS classes. Ordering
(comparison) relationships between QCs are also defined as well
as aspects of their offering/use in connection to pSLSes. Finally,
the operations required for building external QCs and therefore
QoS-based inter-domain services are defined and discussed in relation
to the supporting service management and TE functionality: QC advertisement
and discovery, classification, mapping, binding and their implementation
in DiffServ IP networks.
Further
reading:
M.P.
Howarth, P. Flegkas, G. Pavlou, N. Wang, P. Trimintzios, D. Griffin,
J. Griem, M. Boucadair, P. Morand, H. Asgari and P. Georgatsos,
"Provisioning for Inter-domain quality of service: the MESCAL
approach," IEEE Communications Magazine, June 2005. [pdf
document]
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. [link] |