Core Network Virtualization Management Solution

Release Date：2015-03-24 By Zhang Maopeng Click：

Challenges
Increased competition in the telecom industry has meant that traditional telecom operators are facing serious challenges from OTT providers. The growing popularity of multimedia applications has led to slow growth in voice revenue and a decline in operating profit. The surge in mobile data traffic requires large-scale investment into upgrading telecom infrastructure. To address these issues and reduce capex and opex, operators have studied virtualization technology, which has mature IT functions. Virtualization technology creates new issues for the management of a core network system.
A virtual core network system comprises physical devices, virtual devices, and NE applications. These are located on and managed by the physical layer, virtualization layer, and NE application layer, respectively. The management software on each layer may be provided by different vendors. A challenge for the virtual core network system is to coordinate, monitor, and manage different management software offerings and to facilitate network O&M.
Another challenge for the virtual core network system is to orchestrate resources and deploy them onto the cloud platform rapidly and automatically.
A virtual core network system dynamically allocates virtual resources according to the current traffic condition. Therefore, policy and resource management caused by dynamic resource adjustment is also a challenge.

Solution
Management and network orchestration (MANO) is based on the ETSI NFV architecture and comprises orchestrator, virtual network function manager (VNFM), and virtual infrastructure manager (VIM). MANO is added to the corresponding physical NEs of the core network system. A virtual core network system is managed on four layers: physical, virtualization, NE application, and service management (Fig. 1).

Physical Layer
The physical infrastructure manager (PIM) can be used to manage common hardware, such as COTS servers, network switches, and storage disk arrays, in a virtual environment in order to provide a unified, stable, reliable, efficient physical infrastructure for the virtualization layer.

Virtualization Layer
The virtualization layer supports multiple hypervisors, including KVM, XEN and ESXi, and provides diverse VIM platforms such as OpenStack, VMware, and TECS. The virtualization layer provides a virtual hardware infrastructure for the NE application layer and creates an efficient, reliable, manageable operating environment for applications.

NE Application Layer
The NE application layer supports virtual NEs such as vEPC,vIMS and vEMS. It introduces a VNFM module to manage the lifecycle of each virtual NE. This module is responsible for automatic deployment and elastic capacity expansion. The NE application layer can also work with the orchestrator to orchestrate virtual network services.

Service-Management Layer
The service-management layer contains the OSS/BSS and orchestrator. The new orchestrator module orchestrates virtual network services, which means it manages the lifecycle of core network services and NEs, manages network service policies, and orchestrates global resources.
Each layer of the virtual core network system manages the resources deployed on it. Resources on the physical layer are managed by the PIM, and those on the virtualization layer are managed by the VIM. The orchestrator and VNFM coordinate to orchestrate and deploy core network services. Resources on the NE application layer are managed by the EMS. The OSS/BSS functions as an integrated network manager to globally monitor alarms and performance statistics on the service layer. Alarms on the physical and virtualization layers are reported via the VNFM to the EMS, which performs a correlation analysis of the alarms generated on the virtualization and NE application layers and reports these alarms to the OSS/BSS. In this way, alarms can be located and handled in a unified manner.

Value
ZTE’s core network virtualization management solution includes core network NE management, cloud platform management, and hardware management. The solution is
● standardized. At present, more than 50 network operators, telecom equipment vendors, IT equipment providers, and technology suppliers have joined the Network Function Virtualization Industry Specification Group (NFV ISG) since the group was established in ETSI in October 2012. The NFV ISG aims to use standard IT virtualization technologies as well as the industry’s standard large-capacity servers, storage devices, and switches to carry network software functions and flexibly load and deploy software on data centers, network nodes, and clients. This can speed up network deployment and adjustment, simplify service deployment, improve network generalization and adaptability, and eventually lower network capex and opex. ZTE’s core network virtualization management architecture complies with the ETSI standards.
● open. The solution has hierarchical management architecture. Physical devices such as COTS blade servers, switches, and disk arrays are used on the physical layer and are independently managed by hardware-management software. The virtualization layer supports OpenStack, VMware and other types of cloud platforms. The NE application layer offers EPC, IMS, EMS, VNFM and other NE applications. NEs can open their capabilities and interact with VNFM, and NE services can be orchestrated. The VNFM provides open REST interfaces for interconnection with a third-party orchestrator. The OSS/BSS functions as an integrated NMS, and the EMS supports interoperability with a third-party OSS/BSS. The orchestrator complies with ETSI specifications and offers open REST interfaces for interconnection with the VNFM. As the capabilities of interfaces between different layers become more open, operators have more choices in operation and hardware purchase. This increases system openness and compatibility.
● automatic. In a virtual core network, services and NEs are managed in an automatic way. The whole process of network service and NE lifecycle management is automatically implemented, and the processing time is shortened from a couple of weeks or even months in the physical NE era to a few minutes in the virtualization era. This makes it much easier for operators to deploy new services and lower their opex.
● intelligent. In a virtual core network, policies on how to use system resources can be specified, and current usage of resources can be viewed dynamically on the orchestrator. Fewer resources can be used in low-traffic cases, and more resources can be occupied in high-traffic cases. In this way, resources can be dynamically allocated and released, and energy and capex can be saved.

Customer Benefits
ZTE’s core network virtualization management solution brings the following benefits for operators:
● central monitoring, hierarchical management, and simple O&M. System resources can be monitored in a centralized manner. The orchestrator provides a global resource management view for monitoring allocation, alarm and performance of virtual and physical resources. The OSS/BSS/EMS monitors NE application resources. A standalone maintenance UI is provided on each layer to meet operator needs for independent O&M and hierarchical management.
● one-click network service management and short O&M cycle. Core network service management includes service deployment, capacity expansion and service orchestration and can be implemented with one click on the UI. This greatly simplifies system O&M, shortens system deployment and capacity expansion cycle, and helps operators rapidly roll out new services and cut down O&M costs.
● elastic NE expansion and low equipment capex. While the system is running, resources can be dynamically allocated and occupied according to traffic load. This helps operators improve resource efficiency, consume few energy, reduce carbon emissions and lower equipment capex.