OSS/ BSS

Verizon’s next-generation network based on network functions virtualisation (NFV) and software-defined networking (SDN) is rapidly taking shape.

Working with Dell, Big Switch Networks and Red Hat, the US telco announced in April it had already brought online five data centres. Since then it has deployed more sites but is not saying how many.

Source: Verizon

“We are laying the foundation of the programmable infrastructure that will allow us to do all the automation, virtualisation and the software-defining we want to do on top of that,” says Chris Emmons, director, network infrastructure planning at Verizon.

“This is the largest OpenStack NFV deployment in the marketplace,” says Darrell Jordan-Smith, vice president, worldwide service provider sales at Red Hat. “The largest in terms of the number of [server] nodes that it is capable of supporting and the fact that it is widely distributed across Verizon’s sites.”

OpenStack is an open source set of software tools that enable the management of networking, storage and compute services in the cloud. “There are some basic levels of orchestration while, in parallel, there is a whole virtualised managed environment,” says Jordon-Smith.

 

This announcement suggests that Verizon feels confident enough in its experience with its vendors and their technology to take the longer-term approach

“Verizon is joining some of the other largest communication service providers in deploying a platform onto which they will add applications over time,” says Dana Cooperson, a research director at Analysys Mason. 

The Verizon data centres are located in core locations of its network. “We are focussing more on core applications but some of the tools we use to run the network - backend systems - are also targeted,” says Emmons.

The infrastructure is designed to support all of Verizon’s business units. For example, Verizon is working with its enterprise unit to see how it can use the technology to deliver virtual managed services to enterprise customers.

“Wherever we have a need to virtualise something - the Evolved Packet Core, IMS [IP Multimedia Subsystem] core, VoLTE [Voice over LTE] or our wireline side, our VoIP [Voice over IP] infrastructure - all these things are targeted to go on the platform,” says Emmons. Verizon plans to pool all these functions and network elements onto the platform over the next two years.   

Red Hat’s Jordon-Smith talks about a two-stage process: virtualising functions and then making them stateless so that applications can run on servers independent of the location of the server and the data centre.

“Virtualising applications and running on virtual machines gives some economies of scale from a cost perspective and density perspective,” says Jordon-Smith. But there is a cost benefit as well as a level of performance and resiliency once such applications can run across data centres. 

And by having a software-based layer, Verizon will be able to add devices and create associated services applications and services. “With the Internet of Things, Verizon is looking at connecting many, many devices and add scale to these types of environments,” says Jordon-Smith.  

 

Architecture

Verizon is deploying a ‘pod and core architecture’ in its data centres. A pod contains racks of servers, top-of-rack or leaf switches, and higher-capacity spine switches and storage, while the core network is used to enable communications between pods in the same data centre and across sites (see diagram, top).

Dell is providing Verizon with servers, storage platforms and white box leaf and spine switches. Big Switch Networks is providing software that runs on the Dell switches and servers, while the OpenStack platform and ceph storage software is provided by Red Hat.  

Each Dell rack houses 22 servers - each server having 24 cores and supporting 48 hyper threads - and all 22 servers connect to the leaf switch. Each rack is teamed with a sister rack and the two are connected to two leaf switches, providing switch level redundancy.

“Each of the leaf switches is connected to however many spine switches are needed at that location and that gives connectivity to the outside world,” says Emmons. For the five data centres, a total of 8 pods have been deployed amounting to 1,000 servers and this has not changed since April.

 

This is the largest OpenStack NFV deployment in the marketplace

 

Verizon has deliberately chosen to separate the pods from the core network so it can innovate at the pod level independently of the data centre’s network.

“We wanted the ability to innovate at the pod level and not be tied into any technology roadmap at the data centre level,” says Emmons who points out that there are several ways to evolve the data centre network.  For example, in some cases, an SDN controller is used to control the whole data centre network. 

“We don't want our pods - at least initially - to participate in that larger data centre SDN controller because we were concerned about the pace of innovation and things like that,” says Emmons. “We want the pod to be self-contained and we want the ability to innovate and iterate in those pods.”

Its first-generation pods contain equipment and software from Dell, Big Switch and Red Hat but Verizon may decide to swap out some or all of the vendors for its next-generation pod. “So we could have two generations of pod that could talk to each other through the core network,” says Emmons. “Or they could talk to things that aren't in other pods - other physical network functions that have not yet been virtualised.”  

Verizon’s core networks are its existing networks in the data centres. “We didn't require any uplift and migration of the data centre networks,” says Emmons, However, Verizon has a project investigating data-centre interconnect platforms for core networking.    

 

What we have been doing with Red Hat and Big Switch is not a normal position for a telco where you test something to death; it is a lot different to what people are used to

 

Benefits

Verizon expects capital expenditure and operational expense benefits from its programmable network but says it is too early to quantify. What more excites the operator is the ability to get services up and running quickly, and adapt and scale the network according to demand.

“You can reconfigure and reallocate your network once it is all software-defined,”  says Emmons. There is still much work to be done, from the network core to the edge. “These are the first steps to that programmable infrastructure that we want to get to,” says Emmons.

Capital expenditure savings result from adopting standard hardware. “The more uniform you can keep the commodity hardware underneath, the better your volume purchase agreements are,” says Emmons. Operational savings also result from using standardised hardware. “Spares becomes easier, troubleshooting becomes easier as does the lifecycle management of the hardware,” he says. 

 

Challenges

“We are tip-of-the-spear here,” admits Emmons. “What we have been doing with Red Hat and Big Switch is not a normal position for a telco where you test something to death; it is a lot different to what people are used to.”

Red Hat’s Jordon-Smith also talks about the accelerated development environment enabled by the software-enabled network. The OpenStack platform undergoes a new revision every six months.

“There are new services that are going to be enabled through major revisions in the not too distant future - the next 6 to 12 months,” says Jordon-Smith.  “That is one of the key challenges for operators like Verizon have when they are moving in what is now a very fast pace.”

Verizon continues to deploy infrastructure across its network. The operator has completed most of the troubleshooting and performance testing at the cloud-level and in parallel is working on the applications in various of its labs. “Now it is time to put it all together,” says Emmons. 

One critical aspect of the move to become a digital service provider will be the operators' ability to offer new services more quickly - what people call service agility, says Cooperson. Only by changing their operations and their networks can operators create and, if needed, retire services quickly and easily. 

"It will be evident that they are truly doing something new when they can launch services in weeks instead of months or years, and make changes to service parameters upon demand from a customer, as initiated by the customer," says Cooperson. “Another sign will be when we start seeing a whole new variety of services and where we see communications service providers building those businesses so that they are becoming a more significant part of their revenue streams."

She cites as examples cloud-based services and more machine-to-machine and Internet of Things-based services.