Mambretti, who directs the International Center for Advanced Internet Research at Northwestern University, is recently back from a round of meetings and conferences on advanced communications, including SC14—the 26th annual supercomputing conference for High-Performing Computing, Networking, Storage, and Analysis. His following report highlights macro trends he sees rapidly transforming the communication services and networking landscape:
One key macro trend is the implementation of programmable networking using Software-Defined Networking. SDN is an approach to digital networking that allows network administrators and operators to manage network services through the abstraction of lower-level functionality and core resources. It decouples the control plane where decisions are made about where and how specific traffic is sent from the data plane containing the systems that transport traffic to and from selected destinations.
SDN leverages many new virtualization techniques for implanting significantly higher levels of abstraction for network control and management functions at all layers and across all underlying technologies.
These advances are transforming communication services to allow for powerful new capabilities by migrating foundation resources from those based on generally static implementations to those using on-going dynamic provisioning.
These development are also leveraging many years of progress in programmable networking, including Grid networking, especially architecture based on Open Grid Forum standards, and dynamic networking architecture based on the separation of control and data planes, which has been used for dynamic lightpath provisioning for more than ten years.
Lightpaths are the channels that transport data in optical fiber, a foundation resource for digital communications. Almost all current SDN implementations are based on the OpenFlow architecture and protocols.
The SDN/OpenFlow approach enables every individual traffic stream transiting from one point to another (e.g., between IP addresses) in a network to be identified and directly controlled, dynamically and automatically, in accordance with a wide range of specialized attributes. Consequently, different types of flows can be better matched with network resources. For example, time-critical traffic such as digital media can be expedited over other types of traffic.
100 Gbps Networks
Another major trend is the implementation of significant additional network capacity through the deployment of 100 Gbps paths in major networks. Almost all major network backbones are being upgraded to 100 Gbps paths.
A third trend is the combining of SDN capabilities with 100 Gbps paths to enable optimal utilization of this capacity, as opposed to merely aggregating many small traffic streams.
These approaches are not only allowing network designers to create a much wider range of services and capabilities than can be provided with traditional networks but they are also providing for:
- Many more dynamic provisioning options, including those that can be provisioned in real time;
- Faster implementation of new and enhanced services, such as those that optimize digital media and Big Data applications);
- Enabling applications, edge processes and even individuals to directly control core network resources;
- Substantially improved options for creating customizable networks;
- Much more granulated views into traffic flows;
- Enhanced operational efficiency and effectiveness, especially for traffic engineering, that is, optimally matching network resources to required communication services.
Resource Virtualization Revolution
All major information technology revolutions have been driven by higher levels of abstraction in architecture and implementation than traditional approaches. Today, information technology is undergoing a revolution in resource virtualization, which has been described by such terms as: Architecture-as-a-Service (AaaS), Environment-as-a-Service (EaaS), Software-as-a-Service (SaaS), Infrastructure-as-a-Service (IaaS), Platform-as-a-Service (PaaS), Container-as-a-Service (CaaS), and Anything (and Everything)-as-a-Service (XaaS).
These trends include those revolutionizing networks: Networks-as-a-Service (NaaS), Network-Testbeds-as-a-Service, and others. For networks, SDN has been a key enabler of this type of virtualization. As noted, SDN implementations are transforming the world of networking by providing for unprecedented levels of programmability at all network levels. Consequently, different types of data traffic can be treated separately in accordance with specific requirements, such as low latency, quality, service level agreements, security, routing policy, etc.
Need for Software-Defined Exchanges
Although the many benefits of SDN are well known, especially within and among large data centers, the increasing deployment of SDN in production networks is resulting in many isolated SDN islands being created. Consequently, Software Defined Exchanges (SDXs) are needed to interconnect these islands.
The development of SDXs allows for a fundamental transition from traditional L3 BGP-based peering exchanges. For example, exchanges can begin to incorporate capabilities for dynamic provisioning of L2 and L1 paths, which enhance quality for digital media and high-capacity Big Data streams, rapidly growing segments of Internet traffic.
No production SDX facility exists today, in part because there is no standard approach to SDX architecture. However, various SDX models are being prototyped. For example, the International Center for Advanced Internet Research (iCAIR) and its research partners are designing and implementing one of the world’s first SDXs at the StarLight International/National Communications Exchange Facility. Funding is from the National Science Foundation through the Global Environment for Network Innovations (GENI) program.
This SDX is a multi-domain service enabling federated controllers to directly access individual switches to enable direct control of the traffic streams within those switches. In contrast to more general implementations of 100 Gbps services, this approach enables extremely large-capacity individual data flows to be directly managed to meet application requirements.
SDXs remove the restrictions inherent in traditional L3 BGP peering exchanges, providing many new capabilities for network resource management and control and enabling granulated manipulation of individual network flows; i.e., any given data flow from one point to another can be addressed individually in accordance with attributes required by specific services and applications.
SDN resources can be partitioned to create many different types of networks with different behaviors. This approach elevates the concept of “a network” to a high-level abstraction that encapsulates a collection of “flowspaces” that can be designed with different services, capabilities, attributes, behaviors, and policies, almost without limits.
Conceptually, an SDX can be considered a large-scale virtual switch, within which it is possible to create multiple virtual switches customized for specialized purposes. Within the domain of a single SDN, it is possible to implement an almost unlimited number of distinctly different flowspaces.
The development of SDN and SDX approaches provides major opportunities for next-generation networking, because of the current trend toward high-capacity networks based on 100 Gbps channels. Also, these techniques will support the 400 Gbps and 1 Tbps paths that are being planned. This increase in capacity can support many different types of customized communication services and networks within the same common infrastructure, for example, digital media networks, financial networks, highly secure networks, health care networks, crisis response networks, and so forth.
During the SC14 conference in New Orleans, the StarLight consortium and its research partners designed and staged a series of demonstrations to showcase capabilities of SDXs, including capabilities for provisioning and dynamically controlling individual high-capacity streams transported nationally and international over wide-area networks to, from and around the conference show floor.
Nearly all current implementations of 100 Gbps paths are used to support aggregations of many millions of small data flows. These demonstrations showed the capability of SDXs to utilize extremely-large-capacity individual streams end-to-end to support a wide range of specialized applications in data-intensive science, high-performance digital media, and healthcare based on computation bioinformatics. For example, extremely high-resolution specialized digital media such as 4k media (4,000 pixels horizontal by 2,000 vertical) can be supported across wide-area networks uncompressed.
Only the Beginning
The trends described here are only the beginning of a profound transformation in communication services and foundation technologies, based on new techniques for network programmability enabled by new abstraction and virtualization techniques. These trends are accelerating and will provide many new and powerful capabilities for transporting data worldwide and for applications that have not been possible with traditional networks.
Joe Mambretti, Director, International Center for Advanced Internet Research, Northwestern University; Director, Metropolitan Research and Education Network; firstname.lastname@example.org