Service Providers and Enterprises are spending lot of money to deploy and manage customer premise equipment (CPE). Enterprise sites have dedicated hardware that provide network functions such as firewall, NAT, DHCP, WAN optimization, routing, load balancer, web filtering and IPS/IDS. This approach results in complex design, overprovisioning and delays in delivering service. Software Defined Network (SDN) and Network Functions Virtualization (NFV) are two key transformational technology paradigms that can help service providers to evolve their approach to make network dynamic and agile by providing cloud based network functions. A cloud based customer premise equipment (vCPE) solution can provide services such as security and routing and replace on site physical CPE with a simple Layer 2 device and implementing cloud based network function using commercial off-the shelf (COTS) servers as shown in figure below.
vCPE solution is intended for small and medium enterprise customers . Market adoption of SDN and NFV is still nascent and currently service providers are doing trials to ascertain impacts, CapEx and OpEx savings. These technologies have big impact on how networks are built and operated and thus service providers have setup separate teams and small setups. Some of key concerns are ROI from new and existing network infrastructure, reliability, security and alignment to existing business processes.
System Integration Challenges
vCPE service is expected to be offered to customers though self-care portal where customer can select the required virtual functions, billing model and other network flexibility offerings such as bandwidth provisioning on the portal. The selected services are orchestrated that results in spawning of required network functions virtual machines on the shared pool of resources and enablement of networking using SDN concepts like virtual network and service chaining. The complete fulfilment process is completed in hours/days and not months as it happens today. Many vendors are offering vCPE products but to achieve agility and network programmability, these products have to be integrated with OSS/BSS systems of service providers. Existing OSS/BSS systems may have to be enhanced to support new virtual assets and business models.
With the introduction of network virtualization for realizing service such as vCPE, there will be impact on the traditional design, integration and test activities and thus the system integration methodology has to be realigned. Designers have to look at physical infrastructure, virtual infrastructure, mapping to logical to physical infrastructure, service template and catalogue design, Orchestrator & OSS/BSS integration, VNF EMS OSS integration and self-care and management portal development and integration. Some of consideration that are related to cloud such as scale up, scale down, virtual machine migration and healing are also to be looked at. The integration team has to define and develop various integration use cases for scenarios like order management, billing and service assurance and adapt them to the nuances of agile network. Similarly the testing team has to look at cloud and virtualization aspects apart from functional aspects of network functions. Finally the operation and managed services with increased adoption of automation, implementation of DevOps and use of tools will bring in time and money efficiency. The scope of operation also increases as now customer can entrust complete operation of network functions to service providers and reduce its network managing resource or align them to business related activities.
The dynamic network configuration because of on-demand allocation of resources and sharing the pool of resources brings in challenges in network management. The management tools have to evolve so that the real time events from the network across the various abstraction layers e.g tunnels, overlays etc. enable the operations team to detect, isolate and resolve problems and to perform root cause and impact analysis. The physical and virtual domains are monitored independently and have their own KPI/KQI and thus performance management has to take into consideration both domains and provide a unified view so that the performance management can be done efficiently with a complete network view. Centralization, orchestration and automation bring in a new approach for rollout and management of SDN/NFV solution such as vCPE. This new approach enhances the delivery and operations efficiency that will help service providers to roll out new service/release quickly and lower the operational costs.
Though there are still business and technical challenges in rolling out SDN/NFV solutions such as vCPE but the rapid evolution of solutions, tools and processes are expected that will make new agile and programmable network a reality soon.