JOHN WILLIAMSON FTTX
FTTx sparks network management re-think: gently does it
impede the introduction of new services (especially the dynamically changing cloud-based services). For BT, SDN and virtualisation are part of a wider move towards programmable networks. In its FTTx work the operator is researching so-called “white box” solutions that deploy widely-available network chips into cost-e ective switches and routers. “This enables us to control and deploy much more of the features we need in the network and allows us to do this at a much lower unit cost,” says McRae. “It also allows us to add programmable and model-based concepts and use technologies such as Netconf/YANG and telemetry which make management much simpler.” The Broadband Forum (BBF) is likewise an advocate of advanced software-based techniques. “Our software-deliverable TR- 355 YANG Modules for FTTdp Management uses these techniques to allow operators to configure and control fibre-fed nodes (DPUs) in the periphery of the access network,” states BBF CEO Robin Mersh. ROADWORKS To date, Reconfigurable Optical Add- Drop Multiplexers (ROADMs) have been deployed in the long haul and metro optical networks. More recently, they have started to be targeted at the optical edge. The benefits of software-controlled ROADMs include flexible in-service re-allocation of bandwidth, remote configuration and re- routing and simplified engineering. A recent ROAD-related initiative was the formation of the Open ROADM group in which AT&T is a leading light. The Open ROADM Multi-Source Agreement (MSA) defines interoperability specifications for ROADMs. The group observes that current ROADMs are proprietary systems, with proprietary software inside the network elements and outside of them, to plan, manage and maintain the system. Another concern is that today’s ROADMs retain a lot of fixed internal connections, whereas in an ideal SDN environment, the connections between ROADM elements should be remotely configurable through open interfaces without the need of human intervention. In December 2016 AT&T reported that it had recently implemented in the Dallas area a 100 Gbits/s optical wavelength in its production network using Open ROADM- compliant technology. The 100 Gbits/s wavelength was provisioned using an SDN ROADM controller developed by Fujitsu and integrated into the AT&T Enhanced Control, Orchestration, Management & Policy architecture. In a blog, Andre Fuetsch, President AT&T Labs and Chief Technology O cer, described two goals with these new ROADMs: software control and open hardware specifications. Of the former he wrote: “Software control allows us to better manage and route each wavelength of laser light that comes into each switch. And we’ve already made a lot of progress on that front.”
Next generation networks, controlled more by sophisticated software systems than simply more highly- specified hardware than before are not only blurring the edges of the old local, metro and wide geographies, they are redefining operators’ approaches to both design and operation. John Williamson reports.
JOHN WILLIAMSON
G lobally the deployment, commercialisation and use of the various fibre-flavoured forms of next generation access (NGA) are rocketing. A 2016 Analysys Mason report authored by Rupert Wood, lead analyst for Fixed Networks and Wireless Networks research programmes, estimated that FTTx systems would be available to 1.3 billion premises by 2021. The additional tra c generated by these NGAs has important ramifications for how communications infrastructure and capacity is controlled, operated and allocated end-to-end. Also, intensifying market competition worldwide means current customer and user expectations are running at unprecedentedly high levels. Such considerations are mandating a major overhaul of network management philosophies and designs. In this context, network management centred on and emphasising programmable software is an attractive proposition. “Programmability is a big trend for all
networks,” agrees BT’s Chief Architect, Neil McRae. “It gives us the ability to react faster to changing demands and to manage the inherent complexity in modern networks better.” There are a number of approaches – some overlapping – to increasing network programmability and versatility. SOFT SPOT Software Defined Networks (SDNs) mark a significant shift towards programmability and away from static, proprietary equipment-centric network management. As does Network Functions Virtualisation (NFV), with its implementation of functionality as software run on industry standard systems. As noted by the Fibre to the Home Council Europe’s 2016 FTTH Business Guide, in fibre access networks SDN facilitates the automation of hardware provisioning, and the programmability of features governing the behaviour of network devices. The Guide adds that an access network without SDN programmability and NFV flexibility will
Max Penfold, International Sales Manager of broadband access test house UTEL, says demand for FTTx in general, and GPONs in particular, is outstripping the ability of some incumbents to deliver, in the process opening the door to new players. Once in place, though, FTTx supplies extra bandwidth to support a plethora of new high-speed services. As with expanded physical transportation links such as highways, in FFTx-enabled environments tra c levels rise to fill the available new capacity. According to the 2016 Cisco Visual Networking Index, on a global scale in 2015 households with high-speed fibre connectivity generated 58 percent more tra c than households connected by DSL or cable broadband. This puts a premium for both incumbents and new providers on programmable network management solutions able to flexibly provide bandwidth where and when it’s required. BUILD IT AND THEY WILL COME
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| ISSUE 8 | Q1 2017
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