Key Concepts and Design Considerations
The HPDMnet initiative represents a fundamental departure from traditional methods of providing digital media services. Today, providing general high quality digital media services on traditional networks is a major challenge. Yet, many emerging and proposed future applications require capabilities far in excess of what these existing services can provide. For example, current techniques used for large scale digital media streaming are severely limited because traditional networks have been designed to manage many small flows of information. They were not designed to support relatively few extremely large scale streams or complex blends of large and small streams. Also, traditional services have been designed to operate on a fairly static infrastructure, provisioned as a centrally controlled series of hierarchical layers. Traditional basic support service is provided by Layer 3 routing. Standard L3 routing techniques do not sufficiently support very large numbers of long-duration, high volume streams, especially when optimization techniques are required, such as multicast.
The HPDMnet initiative is addressing these challenges by taking advantage of seven recent innovations in architecture:
Virtualization: Currently, there is a macro trend to virtualization in all areas of information technology. The HPDMnet initiative is creating new methods that allow for virtualization of network resources at all layers and for all components so that they can be integrated into new types of distributed environments.
Close Integration of Services and Support Capabilities: The HPDMnet design allows for extremely close integration of service requirements and underlying support resources, in part, through the use of virtualization techniques, but also through specialized signaling and API processes, including those based on web services.
Infrastructure as a Service (IaaS): The HPDMnet architecture is based on the premise that all resources, including physical infrastructure, should be made available as a service, which allows for a high degree of flexibility, customization, resource utilization and optimization, reliability, and dynamic response to changing requirements.
Programmable Networks: The HPDMnet design takes advantage of new approaches to accessing and utilizing network resources, techniques that transform network resources from static resources to capabilities that can be configured and reconfigured dynamically.
Multi-Layer Services: A major limitation for digital media services on today’s networks is that they relay almost exclusively on L3 routing. HPDMnet is developing L1 and L2 techniques that provide for powerful complementary capabilities, and, in some cases, replacement services that are exclusively based on L1/L2 services.
Multi-Domain Service Provisioning: The HPDMnet architecture was designed from inception to be interoperable across domains around the world. A basic premise is that such services must interoperate as part of global environments. This research initiative builds on a foundation of multiple other research efforts undertaken through other successful research project by the members of the consortium related to dynamic L1/L2 inter-domain provisioning.
Experimental Testbed Investigations: The HPDMnet architecture is being shaped not by abstract theories or lab simulation with test data, but with capabilities not possible to implement on traditional networks. Experimental HPDMnet research is being conducted on a large scale international research testbed using actually high volume digital streams.