Current Trends in IP and Optical Transport Integration
Harald Bock, CTO Technology Strategy at Coriant, explores the changing market dynamics in a new networked world.
The market dynamics of the communications industry continue to change based on the evolving needs of the consumer and business world. Services like private and public cloud storage, mobile broadband, streaming video, and elastic computing are some of the trends that are creating a tidal wave of data demands in networks. This “hyper-growth” of data demands presents both opportunities and headaches for service and network providers dealing with data and bandwidth-thirsty end-user applications.
As businesses and consumers increasingly embrace these new applications they are creating new setof requirements for the network providers that support them. With these changes in the traditional networking landscape a new class of service providers has emerged offering telecom, data and cloud-based services.
There is no “one size fits all” with this new network environment and a more dynamic, flexible configuration is now the requirement for future networks. These networks must be able to support:
● Bandwidth on-demand to match the flexibility of compute and storage technologies
● Sustained multi-tenant data architecture
● Expectations by customers for greater network efficiency with even more use cases
● Scalable and “always-on” resiliency
● More rapid service deployments to support the demands of unpredictable traffic growth
The history of Internet Protocol (IP) and optical integration started with an approach to use Dense Wavelength Division Multiplexing (DWDM) Point-to-Point transport between IP network elements only at certain points in the network. This approach supported the technology needs of the time since there was a hybrid mix of network technologies. As IP-everywhere is the primary transmission protocol today, and into the future, further integration of the IP and optical transport layers is required for efficiency and responsiveness to network demands.
The existing circuit layer of the network was initially combined with a purely transparent IP-over-DWDM transmission structure for full end-to-end network coverage. The target of this new and simplified network architecture was a leaner network requiring a reduced number of interfaces. However, the disadvantage of this structure was found to be difficult in the operational complexity and capacity limitations prevented near-term deployment.The different equipment layers required separate teams to support the network from an operational perspective. This challenged network operators to quickly and efficiently manage network operations on a day-to-day basis.
To achieve a simplified, more scalable and easier to operate network architecture, the integration is not only required at the equipment level but also in network management and the services level to support provisioning efficiency. With the increased focus of IP optical integration on the network management and control plane, network operators have recently started to deploy converged IP optical networks to increase the efficiency of their networks.
This in turn, has moved the focus of IP and optical integration back towards the data plane. Efficiently combining IP and optical transport required additional features, e.g. the regeneration of IP over DWDM channels within the DWDM network which is still a new feature today. Another key requirement is the combination of IP traffic with optical transport’s aggregation layers managed under a single OSS system. Effectively, this means that IP optical convergence has evolved significantly from unmanaged IP over DWDM transmission towards IP over multi-layer transport with integration on data plane, network management and network control levels.
By integrating networks in this manner, the transition towards a software defined network (SDN) is prepared. SDN is still aspirational for many organizations, but the reality is that 2015 is becoming the watershed year for the concept. Operators are finally realizing the value of the opportunity and making the move from research and lab trials to field trials and actually implementing it in their networks. Indeed, analysts are particularly positive about the surge in SDN implementation, with IDC forecasting it to become a $3.7 billion market by 2016.
“There is no ‘one size fits all’ with this new network environment and a more dynamic, flexible configuration is now the requirement for future net works”
Implementing SDN provides radical cost and time-saving benefits for enterprises and operators alike. The most obvious of these is the opportunity to automate activities via programmable controls, which enables organizations to mechanize functions, reduce the risk of human error and consequently increase business efficiency. SDN also decreases the time taken to dimension and provision resources for applications, while reducing the complexity of provisioning and configuring diverse resources. In this sense SDN acts as a network “compiler” by translating complex operational management into a holistic, abstracted programming model.
Revolutionizing business and consumer data
With the new multi-layer optimized network structure, the efficiency of a packet-based network and the cost advantages of optical transport networks come forward. This offers a number of opportunities for future SDN-controlled L0-L3 networks.
Programmability: The quickest way to introduce and adjust services is to make the network more programmable. This means making the network fully adaptable to the evolving needs of end users, network operators, and the applications themselves. The automation of network resources will enable service providers to unlock new service revenue opportunities, such as transport as a service, bandwidth-on-demand and scheduled bandwidth; adapt to real-time network changes, such as virtual machine migration; reduce overall network complexity; and use network resources more efficiently.
End-to-end multilayer integration: The shift of end-user services and applications to private and public cloud networks places even more importance on agile and efficient integration of compute and storage resources. This is across multiple geographies, such as access, metro, core, and protocol layers, such as wavelength, Optical Transport Network, Ethernet and IP/MPLS. SDN plays an important role in harmonizing capabilities across this broad range of resources and enabling a true end-to-end global view of the network.
Flexibility: Of particular importance is optical layer flexibility. The physical layer of the network has seen significant technology advances, including coherent transmission, colorless/directionless/ contentionless ROADMs, flexible-grid-enabled super-channels, and photonic mesh. To achieve maximum flexibility, scalability and resiliency, service-provider transport networks must fully leverage such technology innovation at the photonic layer to meet the performance requirements of cloud-centric residential and enterprise applications. That can only be fully realized with SDN, through inclusion of the optical layer as legitimate alternative to pure packet forwarding as application needs dictate.
Openness: Packet optical transport infrastructure networks are multi-vendor and multi-technology by nature. They therefore depend on standards-based protocols to enable interoperability at the physical layer. SDN enables an unparalleled administering of multi-vendor networks and architectures with an open and collaborative software-based development process focused on end-user applications and optimized for enhanced-network programmability.
The future evolution of IP and optical transport will open up a world of data-rich opportunities to businesses and consumers alike. As service providers transform their existing network resources and architectures to adapt to this new networked world a number of key network attributes need to be addressed, and SDN technologies will play a critical role in each.