The telecom world is rapidly changing, with software playing a prominent and strategic role in all aspects of operator networks. In the broadband world, the big move afoot is software defined access -- also known as SD-Access or SDA -- where hardware is disaggregated and software is reorganized and placed on commercial servers or on X86 silicon in broadband equipment.
In the January 2018 IHS Markit global survey, "Router and Switch Vendor Leadership, Service Provider Survey," operators revealed the companies they viewed as the top service provider router and switch vendors across a number of measures. Not surprisingly, the top four vendors collectively sharing 85% of router revenue market share were also the top four in a number of categories, although their rankings varied.
Juniper, Cisco, Huawei and Nokia excelled at delivering on all the following five criteria operators considered to be most important:
Service providers named Cisco, Nokia, Juniper, Huawei and Brocade the top virtual router (vRouter) vendors, according to this survey. Operators trust and rely on router manufacturers, so it is natural to expect they purchase subscriber management software from the router manufacturer that currently supplies their physical edge router, with included broadband network gateway (BNG) functionality.
In the "Routing, NFV, and Packet-Optical Strategies, Service Provider Survey," a companion IHS Markit survey of the same operators in January 2018, a whopping 92% of operators with broadband networks said they will deploy or plan to deploy, virtual BNG (vBNG). This finding underscores a real intent to follow through on the part of broadband operators.
However, a new battleground has emerged over who will supply the BNG subscriber management software. In today's broadband networks, the BNG function resides in physical edge routers built by major router manufacturers. These router manufacturers have all released virtualized, software-only versions of router functions running on commercial servers (known as vRouter software), and the subset of vRouter subscriber management functions, (called vBNG). Broadband equipment vendors have started developing their own BNG and router software in parallel, although their solutions are more limited to the specific needs of the broadband access network.
In this shift to become more software focused, questions remain. It was only at the beginning of this year that ADTRAN, Calix and other broadband vendors began offering vBNG software. In fact, vBNG is part of their product strategy to disaggregate passive optical network optical line terminal (PON OLT) and digital subscriber line access multiplexer (DSLAM) hardware, and to add software-defined networking (SDN) control software running on servers or their own equipment.
SDN and other control software are used to integrate the operation of disaggregated hardware, not a simple task for broadband vendors. However, it is a fairly straightforward engineering effort to move vBNG software into this new architecture. The challenge is timing: how soon can this new vBNG software match the feature set of existing BNG software from router companies? In next gen SD-Access architectures, the vBNG is located close to -- or even inside -- distributed OLT and DSLAM equipment, rather than in a large edge router residing upstream, where much OLT and DSLAM traffic is aggregated.
While there are many considerations to keep in mind, when choosing how to redesign a broadband network with SD-Access principles, the new option of moveable and distributed vBNG software opens up new decisions for broadband operators. Some are already experimenting -- making small deployments of disaggregated OLTs and DSLAM, and testing whether the broadband vendors' vBNG software will be workable. Verizon announced an early deployment in the first quarter of 2018 for next-generation PON2 (NG-PON2) with the BNG software running on an x86 inside Calix gear. AT&T is testing Calix and ADTRAN gear and software locating the vBNG software in a network functions virtualization (NFV) environment on commercial servers. Both operators are following a strategy of purchasing vBNG from broadband equipment manufacturers. The edge router role is returned to the original role of routers -- for efficient traffic aggregation and transmission.
Choosing the incumbent router vendor's vBNG software will allow operators to continue their current subscriber management operations. However, at least two big operators have shown a willingness to change this practice. Only time will tell, if broadband operators will choose their vBNG software from their broadband aggregation vendors, rather than from their router vendors.
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— Michael Howard is executive director of research and analysis of carrier networks at IHS Markit. Follow him on Twitter @MichaelVHoward or @IHSMarkit.
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