Cloudization and Cloud Native: An Inevitable Road to Deepening Telecom Transformation

The Need for In-Depth Cloudization

After successful tests and trials in 2015, network function virtualization (NFV) has been gradually put into commercialization around the world. More and more operators have decided to introduce NFV solutions when deploying their new service such as VoLTE and IoT or developing existing service such as MBB, so as to achieve the commercial deployment of NFV solutions including vIMS and vEPC.
The introduction of NFV solutions allows telecom software and hardware to be decoupled. In the initial deployment of vIMS and vEPC, the NFV solutions give operators more flexibility in choosing or purchasing hardware types than traditional solutions. This helps operators save hardware investment and reduce the delivery cycle. However, in the initial commercialization, the NFV solutions triggered by a single service requirement are still similar to traditional networks in terms of hardware configuration, deployment, and O&M model. Therefore, there is tremendous space for improvement in resource sharing and optimization, user experience, and service innovation.
The number of hardware resources is accurately configured to meet the capacity need of a single service, which does not allow the resources to be shared between different types of network services. The peak and valley effect of different services cannot be utilized for resource complementation, so operators are unable to save more investment in resources.
Network infrastructure designed in accordance with traditional network sites cannot fully utilize the characteristics of cloud computing to provide higher availability for virtual network function (VNF) applications. Moreover, as infrastructure resources are centralized in traditional sites, a flexible on-demand deployment of VNF applications cannot be realized according to the difference of components in service processing characteristic, regulation requirement and impact on user experience.
Although traditional NEs are softwarized with NFV, they are still a closed software system that only provides traditional telecom functions. Any new feature or function must be customized by existing VNF vendors, restricting the development of new services.
Therefore, the transformation of traditional telecom based on NFV commercialization still needs further cloudization in aspects ranging from network resources to applications.

Cloudization and Cloud Native Become a Common Demand

Building networks with cloudized and componentized VNFs over distributive data centers has been the target of big operators around the world.
A unified resource pool for the whole network based on multi-tier distributive data centers provides shared resources for all nodes in a traditional telecom network from fixed to mobile, from voice to data, and from access to core. Combined with the policy-based automated deployment and elastic control functions of MANO, services creation on demand and resources allocation on demand can be realized.
Oriented to distributed data centers, the componentized and cloudized VNF applications are reconstructed as stateless design with separate data layers for all processing logics and also separate control plane processing from user plane processing. Facing different scenarios with different SLA requirements, resource consumption and regulation, each component of VNF can be flexibly deployed onto any place of multi-tier distributive data centers to ensure optimized resource utilization and best user experience.
Due to the homogeneity of public telecom services, traditional network operators can only compete with each other and attract common subscribers through conventional means such as improving network coverage with increasing investment and saving costs, which, however, reduce the revenue and profitability of public telecom market. Scenario-oriented service provision to industrial customers and segmented markets has become the focus of future business development for operators, which has been added in 5G network standards as one of the most strategic requirements. To adapt to the requirements of the industries and segmented markets in a more flexible and faster manner and to accelerate innovations, cloud native has begun to be the common pursuit of operators for cloud networks. Cloud native shall have the following features:
●  Microservices: Based on the microservice architecture, VNF can be decoupled into a group of microservices that are independent of each other and implement their own independent business functions. All the microservices are decoupled from each other, and deployed and upgraded independently. With DevOps tools introduced, agile customization and continuous delivery of VNF is achieved. Each common microservice uses open and lightweight API interfaces to allow and facilitate third-party partners to reuse them for new service and application innovation.
●  Container-based deployment: As a lightweight virtualization technology, containers can save more hardware resources than VMs. The container technology (such as Docker) also delivers applications in a container package (Docker Image), which allows applications to be shared in different teams and deployed in any environment to support continuous iterative development of VNF and accelerate the speed of updating and delivery.
●  Automated maintenance: Automated lifecycle maintenance is provided for all cloud application instances serving different customers in different scenarios by the MANO platform, which maximally improves maintenance efficiency.
●  DevOps R&D model: To satisfy the challenge of fast delivery, the DevOps model is used to divide a R&D team according to the service. Compared with the traditional team divided by tasks, the DevOps team is responsible for the service in its entire lifecycle from development to deployment and maintenance. Each DevOps team that is organized to deal with all different tasks focusing on one service operates in an agile model, which means the team upgrades and maintains the service it is responsible for in a more frequent way with minor changes. Compared with the conventional waterfall development model, DevOps allows services to be delivered at a higher update speed due to its higher communication efficiency, minor changes and highly automated environments.

ElasticNet Leads the Network Transformation

ZTE's ElasticNet solution provides unified infrastructure including software and hardware, VNF applicaitons and MANO system, fully supporting telecom networks in transforming to cloudized networks and even in smoothly evolving to be cloud native (Fig. 1).

●  Cloud resource: As the NFVi/VIM solution, ZTE's Tulip Elastic Cloud System (TECS) platform provides operators with shared cloud resource services for network transformation based on SDN interconnected multi-tier distributive data centers. Oriented to different resource requirements from different applications and the requirement of smooth evolution to cloud native, the TECS platform can support hybrid resource services including virtual machines, containers and bare metal hardware. Based on open source technologies such as Openstack/KVM and Kubernetes/Docker, TECS is enhanced in function, performance and reliability to better meet the telecom needs.
●  Cloud service: From fixed to mobile and from access to core, ZTE supports operators in end-to-end transformation of their traditional networks into cloud networks. In addition to inheriting all conventional functions and features, ZTE's VNF software is reconstructed to be stateless and componentized based on telecom cloud software architecture, enabling the separation of control and user planes and the cross-DC deployment. Based on cloudization, ZTE is the first to further decouple VNF components into independent microservices and provide the cloud native VNF solution to support scenario-oriented service customization and continuous delivery, which enables operators to respond to changing business chances and innovations more quickly.
●  Cloud maintenance: As a MANO solution integrated with the policy-based intelligent assurance system, ZTE's vManager provides policy-based, real-time, and automated lifecycle management for cloud applications. Based on decoupled microservices, the vManager provides operators with enhanced DevOps services from design, testing to deployment and maintenance at the granularity of a microservice, and with microservice discovery and binding support for cloud native applications.

ZTE's ElasticNet offers an end-to-end cloudization and cloud native solution for operators to deepen their telecom network transformation. Based on distributive data centers, the cloudized and componentized VNF applications help operators maximize resource sharing and utilization efficiency, and implement most efficient cloud network maintenance through the policy-based automated cloud O&M system. With decoupled microservices, the cloud native VNF solution supplied by the ElasticNet not only can support agile development and continuous delivery of new service features but also can be reused by third parties for fast innovation, which gives operators more agility to face challenges of future business expansion.