For Network Slicing, Active Service Assurance Can Help You Keep Your SLA Promises


Next-gen mobile technologies will set the stage for operators, communication service providers, and hyperscalers to make bold promises to their customers. Learn how virtual test agents gives visibility of the network edge to help keep those promises.

It’s almost become a telecom tradition for operators to push a great new offering into the market, only to eventually struggle with maintaining quality and delivering a great customer experience as the service matures. The stumbling blocks were always going to be there, but because service assurance wasn’t planned from the start, operators kept themselves in the dark. By the time they were able to turn on the light with a proper service assurance strategy, upwards of a year or more may have passed. And historically, operators have paid the price in frustrated consumers.

Things are different with 5G network slicing and all the mission-critical services it is expected to support. The stakes are much higher, necessitating that service assurance be baked-in from the start. Operators can plan how 5G networks will be sliced to meet customized performance needs in an expanding range of verticals. While approaches will vary by application, stringent demand for service level agreements, unlike anything they’ve had to provide before in the mobile network, are a constant. Missing the mark could mean regulatory fines and SLA violations that eat significantly into revenues. Even more serious, however, is the potential fallout from issues that affect emergency services, public safety, smart cities, or autonomous cars, just to name a few.

Guaranteeing great experiences in networks that constantly change

Spirent has worked closely with chip vendors, device and network equipment manufacturers, and operators on 5G testing. Working across the full ecosystem has given us a unique vantage point for triangulating issues, and we continue to see immediate areas of concern: the dynamic nature of network slicing where the network is continuously reconfigured on the fly to meet the ultra-low latency, bandwidth, and compute demands of specific applications. Every time this happens, the network is changed in significant ways. It’s a process that happens over and over in 5G networks.

The core network, which used to be purpose-built, dedicated hardware, now with 5G, is virtualized and disaggregated to deliver enhanced performance. The control plane and user plane are now separate and independently configured. To meet latency and/or compute requirements, components of the core are being pushed to the edge and far edge, introducing a new layer of complexity that inevitably results in performance issues and configuration challenges.

Previously, turning up new network infrastructure was a manual practice that could take weeks or months. Testing and validation were often the long poles in the tent, requiring the use of specialized physical test equipment and manual processes, including a lot of drive testing. In 5G networks, testing needs to be dynamically triggered, occurring in seconds or minutes. That means it must become software-based, take place in the operational network, and be part of an automated workflow. In other words, the testing conducted to assure services needs to be part of how the service is designed.

Some infrastructure providers will shout from the rooftops that they plan to handle assurance and QoE requirements in the network gear they deliver. But the simple fact is if these built-in telemetry capabilities are dependent on traffic flowing through, limiting the use for activation and change management use cases and often aren’t used to the full extent based on the impact they have on resources hindering their use to ensure critical SLAs will be met. The industry has not quite woken up to this fact yet, and our cutting-edge work in the lab with 5G tells us there will absolutely be issues, from missed latency targets and lack of resources to misconfigurations and beyond. These potential issues can only be solved with automated, continuous, proactive testing that can detect fleeting flaws as they happen, isolate responsible network functions, and provide actionable guidance to network management and orchestration layers.

Virtualized assurance gives visibility of the network edge

Let’s say a customer needs an ultra-low latency network slice for a particular application like augmented reality or connected vehicle guidance. 5G makes it possible to dynamically create network slices where core network functions and application servers are pushed to multi-access edge computing (MEC) nodes, significantly reducing service latency.

But how do you ensure the new slice will work after it is instantiated? 5G service assurance will need to deploy virtualized test functions (called Virtual Test Agents, or VTAs) to MEC nodes. These VTAs will then pretend to be users or other parts of the network and perform tests on distributed network functions to make sure they will deliver the low latency or other critical performance needs of the end user. Once the service is up and running, the entire network slice can be monitored to ensure end-to-end performance SLAs are continuously met.

5G automation use cases for early deployments

We recommend getting started with a basic set of automation use cases that lay a foundation for broader automation initiatives, but don’t require all elements to be in place:

  • Service turn-up and activation: Automated validation of new services, network slices, and network functions before they go live. To automate these workflows, virtualized service assurance systems must feature a cloud-native design that allows rapid integration with orchestration and back-office systems. 5G VTAs need the ability to accurately mimic real-world network functions and devices, so they can test new functions, slices, and services in advance of actual users. Applying this type of automation for early 5G deployments has been proven to accelerate turn-up and activation by a factor of ten for Tier-1 providers. There is a heightened importance in 5G since manual techniques are no longer viable.

  • Service quality monitoring and fault isolation: The ability to proactively and continuously test service quality and performance across the end-to-end network and automatically isolate issues to specific network functions or infrastructure. In 5G networks, we see an explosion of applications that send traffic only at specific times or when certain conditions are met (e.g., alarm systems, IoT sensors, business applications, etc.). Virtualized service assurance systems need to be able to proactively test these services and underlying network slices with automated workflows to ensure they work when called upon. The systems also must be able to test any part of the network, including the radio interface, to rapidly isolate issues before there are major disruptions for customers. Automating these processes for 5G NSA is already saving Tier-1 providers millions of dollars annually in the form of reduced operational troubleshooting expenses. With the increased complexity of 5G network slicing, demands for SLAs, and new IoT and business use cases, there is an even greater need for automation in this area.

  • Change management: Automated validation of all network changes and upgrades to ensure new services and features meet performance targets without degrading the quality of existing services. In 5G, this requires VTAs that can surround a new or upgraded network function, emulate the rest of the network, and verify performance before the switch to go live is flipped. One key goal of this automation is to avoid “micro” network or service outages where the provider is unaware an issue has occurred until a customer complains. When a Tier-1 mobile provider applied this approach to 3G and 4G networks, undetected issues were reduced by 85 percent. Because two of the key selling points of 5G network slicing are unprecedented latency and speed performance, providers require even lower levels of undetected issues, particularly for critical applications.

5G is here, and in this race, not a single corner can be cut—especially when it comes to network slicing. Next-gen mobile technologies will set the stage for operators, communication service providers, and hyperscalers to make bold promises to their customers. With network-aware service assurance from Spirent VisionWorks, you can keep those promises by bringing the complex, dynamic, and abstract into view.

Read the eBook 5G Active Assurance: Embracing a New Perspective to gain a better understanding of 5G challenges and the many ways active assurance fills in the gaps left by traditional assurance methods.




标签5G, 保障
Ross Cassan
Ross Cassan

Sr Dir Mobility Strategy, Lifecycle Service Assurance

Ross Cassan是思博伦网络、应用与基础设施部门移动基础设施事业部的产品营销总监,负责思博伦旗舰产品Landslide的战略策划、营销与推广。思博伦Landslide支持对整个移动与Wi-Fi生态系统进行端到端测试。此外,他还是宽带论坛(Broadband Forum)与TIA等多种技术标准机构的主要贡献者。Ross于1999年加入思博伦,曾分别在硬件和软件平台的产品管理及营销方面担任过职务。在加入思博伦之前,Ross在Newbridge Networks和Nortel担任营销职位。