By Mohcene Mezhoudi, Benjamin Y. Tang, Jean-Philippe Joseph & Enrique Hernandez-Valencia, Bell Labs Consulting
The advent of Software Defined Networking (SDN) is becoming strategically critical for telecom/datacom and information/cloud Service Providers worldwide. Discussion and writing on the application of SDN in MSO networks have been limited to specific parts of the network. SDN leverages a control plane model with open programmable interfaces to enable the agile and dynamic creation of new services and the orchestrated allocation of network resources. Through this, and by bridging the SDN architectures and solutions between broadband access, hub/headend sites, metro and backbone transport, MSOs will fully leverage SDN principles and their end-end networks. Further, SDN can address the following challenges faced by many MSOs:
- Footprint – Traditional regional boundaries limit ability to provide national or global services. Recent mergers and acquisitions to expand MSO footprint may impact Service Level Agreements (SLAs) and resiliency in the consolidated network. SDN can help mitigate this through a combination of telemetry, data analytics and proactive performance/resiliency management.
- Scale/optimization– Today’s rigid network architectures increase service delivery costs. SDN provides flexibility in dynamically scaling and optimizing resource utilization across IP/optical and throughout metro and backbone networks and in broadband access.
- Growth – Offering services primarily to residential customers limits growth. MSO expansion into new markets and offering competitive new service offerings will enable new growth opportunities. SDN enables the rapid creation of new innovative, revenue-generating services by using solutions such as dynamic and automated service provisioning, network slicing and service chaining end-to-end.
- Capacity – Bandwidth growth is straining broadband access networks. New architectures and technologies such as DOCSIS® 3.1 deep fiber, node splitting, and symmetrical Full Duplex (FDX) DOCSIS will significantly increase broadband access network throughput. SDN can help manage these new complex networks to reduce migration and operations cost.
- Latency – As new ultra-delay-sensitive applications emerge there will be a need to minimize end end latency and maximize resiliency performance and user experience. This can be accomplished by moving latency sensitive functions and applications closer to the end-user and placing them under end-to-end SDN control.
We first present an MSO future network vision with key building blocks cemented by an end-to-end SDN architecture. We propose a multi-layer end-end SDN architecture that can be achieved by implementing an SDN controlled broadband access network and extending SDN to the metro and backbone network with integrated IP/optical transport. We argue for the importance of convergence in both the broadband access and transport network, the metro portion of the MSO network, and the criticality of an SDN-based IP/Optical transport integration. Convergence and integration, which are greatly aided by network virtualization through SDN/NFV, can provide MSOs with an agile, hyper-scalable and cost-effective network fabric to enable automated management, control and optimization of network resources, and the dynamic provisioning of all revenue-generating services. The roles and functions of SDN in broadband access and metro/backbone, as well as the cost benefit of IP/optical integration – in particular, multi-layer protection, will be presented in the remainder of this paper. We conclude by presenting end-to-end SDN based service orchestration that can greatly benefit MSOs in future service delivery.