Information Technology Reference
In-Depth Information
•
The
handling of multicast service requests
, which includes the subscription and
invocation of a multicast customer subscription (cSLA) in order to enable an
end user to consume a particular QoS-enabled multicast stream.
3.8 Caching and CDN Manager
The Caching and CDN Manager (CCDNMngr) is the EIMS subsystem responsible
for all the tasks related to supporting caching and CDNs in ENTHRONE. The aim
of the CCDNMngr is to transparently supplement existing EIMS functionality by
providing alternative content sources that will either improve the performance of
the content streaming or improve the robustness and scalability of the architecture.
Within ENTHRONE, CDNs are considered to be a discrete entity holding
complete, static copies of content and are managed either within a Service Pro-
vider (via the EIMS CCDNMngr) or externally by a separate entity. In contrast,
Caching Nodes are managed as semi-autonomous standalone entities that dynami-
cally cache portions of content. The main functionalities of the CCDNMngr in-
clude to:
•
manage the provisioning of the content
, i.e., inject content into the CDN or up-
load content to the local caches;
•
manage the placement of content in different CDN Nodes
including collecting
statistics used as input to the content placement algorithms;
•
manage the cache policy
which tunes the performance of Caching Nodes (cach-
ing method, replacement policy, etc) based on content usage statistics; and
•
select a Caching Node and/or CDN Node
to stream/deliver content in response
to a consumer request, taking into account different factors such as the con-
sumer location and the state of the nodes.
3.9 Summary
The EIMS defines a set of management subsystems, i.e., EIMS Managers, with
predefined functionalities and interfaces. The functionalities pertain to:
the
end-to-end QoS including QoE
;
•
the actual
service
for managing the customer needs, networks, terminal devices,
and the monitoring thereof;
•
the
adaptation
of the service according to the usage environment context;
•
the aggregation and collection of metadata (including the conversion between
different formats);
•
the
search
for appropriate Digital Items;
•
multicasting
including IP multicast within the last core network domain to-
wards the customer; and, finally,
•
caching
and
content distribution networks
.
•
