Verizon made it official that when it begins its large-scale NG-PON2 deployment during the first quarter of this year, Calix will be one of its main suppliers behind that effort.
The service provider said it will leverage Calix’s AXOS RPm (Routing Protocol module for Layer 3) and the AXOS SMm (Subscriber Management module for disaggregated Broadband Network Gateway).
Verizon will launch its First Office Application (FOA) in Tampa, Florida, this year with plans to extend to more customers as it develops it in that market. The adoption of NG-PON2 ties into the service provider’s broader intelligent edge network concept.
“Because this is a much bigger system that’s part of the broader intelligent edge network, you can think of NG-PON2 as the tip of the spear,” said Vincent O’Byrne, director of technology planning at Verizon, in an interview with FierceTelecom. “We’re shrinking the Verizon network. Instead of having multiple pieces of equipment, we’ll have one type, including a unified transport network and new and improved software based on network controllers to increase our ability to offer new services a lot quicker.”
Using a converged services platform, Verizon will be able to deploy a single access network for residential, business, and mobile services.
Leveraging compliant NG-PON2 optics, the AXOS E9-2 Intelligent Edge System consolidates subscriber management, aggregation, and optical line terminal (OLT) functions into a single point in the network that’s closer to the subscriber. What this means is Verizon will realize significant operations expense reductions with fewer network elements while dramatically improving network automation.
Adtran, Broadcom, Cortina Access and Ericsson, in partnership with Calix, participated in the initial interoperability trial. In July 2016, Verizon named its NG-PON2 vendor partners following a lengthy RFP process.
During the testing process, Verizon examined several features of NG-PON2, including tuning performance, carrying residential and business services on the same platform, and interoperability and conformance testing to meet Verizon optical network terminal (ONT) specifications.
O’Byrne said the service provider is now finalizing agreements with its NG-PON2 vendor partners with the goal of finding platforms that could simultaneously satisfy multiple services.
“We have had these vendors in the lab and what we have been going for NG-PON2 as part of a process we began a few years ago,” O’Byrne said. “We were looking at business service requirements for NG-PON2 to get this platform, which could do several things for us: simplify the CO architecture by combining the subscriber management and OLT into a single platform as well as look at a broader technology, which would allow us to have residential, business and fixed wireless as part of the overall platform.”
By deploying NG-PON2, Verizon can converge many service networks into a single unified network. The service provider can also simplify its operating model by integrating the OLT and subscriber management system.
Verizon, as usual, is taking the road less traveled with its next-gen PON plans—one that it says will assure it has a future-proofed platform. In the near-term, NG-PON2 allows Verizon to move across wavelengths and load balance the rate. The single line rate is symmetrical 10 Gbps and it can offer 8.5 Gbps per wavelength.
While fellow telco AT&T has opted for XGS-PON, Verizon has decided to leapfrog from GPON to NG-PON2. O’Byrne said that Verizon saw the single wavelength systems (e.g., 10G EPON and XGS-PON) “were only possible interim solutions.”
For Verizon, the long-term vision allows the telco to bond wavelengths to get more speed on an existing PON system. The idea of channel bonding is hardly new since it’s already a well adopted method by cable operators for DOCSIS and even telcos bonding multiple copper pairs to increase speeds for DSL and Gfast systems.
In 2016, Calix demonstrated a 20 Gbps system using bonded technology, for example.
“Some of the longer-term capabilities NG-PON2 is the bonding the channels in the wavelengths so you can add a lot of capacity per wavelength,” O’Byrne said. “If a user needed 17 Gbps, you could add two wavelengths to extend beyond the 10 Gbps limit.”
NG-PON2’s channel bonding capabilities will also enable Verizon to leverage and extend network equipment like optical line terminals (OLTs) and optical network terminals (ONTs). As the telco had migrated from BPON, GPON and to NG-PON2, it needed to replace equipment to accommodate the transition.
“As we go forward with BPON, GPON and NG-PON2, it means you have to put in a new piece of equipment,” O’Byrne said. “What this will allow us to do is when we need to go beyond the 8.5 Gbps, we can look at investing in a new type of ONT and shift the costs to a variable cost and allows us to offer the increased speed service to those customers that need it rather than having to make a massive investment across the whole network.”
Besides enhancing speeds and time to market, Verizon is working with Calix and Adtran to establish interoperability. This includes Verizon’s OpenOMCI (ONT Management and Control Interface) specification, which defines the optical line terminal (OLT)-to-optical network terminal (ONT) interface.
“By focusing on interoperability, we can use Adtran ONTs on the Calix platform and vice versa,” O’Byrne said. “This gives is added flexibility to design our systems as we move forward.”
Driving automation, efficiency
Verizon’s ongoing movement to SDN and NFV across its broader set of wireless and wireline networks will drive new automation capabilities for the last mile via NG-PON2 fiber networks.
The service provider will be able to leverage Calix’s AXOS software defined access (SDA) platform. While still an emerging concept, SDA is an open framework for building next-generation access networks that leverage devops, instrumentation, analytics, flow awareness, SDN and NFV. AXOS can accommodate any service physical environment whether it be fiber, copper, or wireless.
O’Byrne said that while Calix and others bring their own flavors of SDA, Verizon has worked with its vendor partners to tailor the platforms to fit their network evolution goals.
“The vendors bring to the table their separate interpretation of some of the SDN technology requirements and we worked with them to support our needs for software defined networks as we go forward,” O’Byrne said. “That’s part of why we’re looking to have that BNG function with the OLT because it simplifies operations and capacity management.”
By combining the BNG function with the OLT, O’Byrne said Verizon can simplify operations, capacity management and quality of service models.
“The OLT is typically made with more off the shelf components and is in line with our future SDN needs,” O’Byrne said. “The gateway function is usually based on specialized chips and this allows us to get more into that software defined network where we want to start using off the shelf components for the OLTs.”
Verizon can collapse functions and service procurement for business and residential users. Traditionally, Verizon had to maintain a separate staff and separate hardware to accommodate businesses and residential customers served by its existing BPON and GPON-based fiber networks.
“Having NG-PON2 allows us to collapse this into one type of OLT that can handle both business and residential customers on the same fiber and same wavelength,” O’Byrne said. “As we get into business services, there’s a different type of optics that you can do so you can have the optics move from one wavelength to another.”
NG-PON2 also improves the network maintenance process. Instead of having to conduct fixes late at night, the service provider can shift traffic onto other wavelengths so a business or residential customer would not be impacted.
“We can have operations fix problems during regular hours rather than maintenance hours,” O’Byrne said. “We have this facility of moving customers onto another wavelength, fixing a PON card and then moving the customers back onto that card.”