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Active Network Testing in Telecom Networks


Today’s telecommunications networks are becoming more difficult to operate effectively. Network operations teams are squeezed between increasing complexity, new technologies (e.g., 5G standalone), shrinking OPEX budgets and the pressure to deliver new and differentiated services, faster. However, the customer still expects a flawless quality of experience (QoE) and will abandon service providers that don’t deliver. Active testing is one technology that service providers are turning toward as they seek to navigate these difficult circumstances. 


Active testing: perfect complement to passive probing

As networks continue to virtualize, passive probing can present challenges. Namely, continued expansion is not always affordable, both from a cost of probing and a cost of data storage perspective. According to one Tier1 service provider in the United States, this means that 80% of user plane traffic will be invisible by 2025. This is where active testing comes in.

Active assurance complements passive probing by providing the following benefits:

  • Directly measures the quality of experience of data, voice, video, IoT, and web services
  • Dynamically monitors quality of service for hybrid networks end-to-end using industry-standard methods
  • Offers real-time measurements for immediate visibility

The scope of active assurance is changing to address the emerging needs of virtual or cloud-based networks and 5G services. A changing service mix, more stringent latency requirements, dynamic network and service topologies, and hard to detect service degradations are some of the key drivers behind this change.

Nova Active: QoE- and QoS-focused service assurance

Nova Active, EXFO’s QoE and QoS-focused service assurance and network performance monitoring solution, is comprised of integrated components for platform and test management, test generation and system integration.

Nova Active’s test catalog includes more than 100 network QoS and user QoE tests, with more than one third measuring quality of experience. Nova Active covers all layers from service to network and throughout the underlying cloud infrastructure. QoE and QoS test capabilities can be deployed from head-end to customer device and from cloud to edge to establish a clear picture of how each domain contributes to service impairments.

Active tests can be generated from Nova Verifier probes available in physical, virtual, container and embedded formats, or via Nova μ-Verifiers that are directly managed by orchestrators. Nova Verifiers and the tests they run are based on common software code, making them fully interoperable regardless of how they are deployed.

Nova Active features

  • QoS- and QoE-aware monitoring, with tests for VoLTE, VoIP, over-the-top video (OTT video), web protocols and more
  • Built for closed-loop, automated solutions with standards-based APIs
  • Proven large scale solution, capable of monitoring from edge to core to cloud, network layers 2 through 7
  • Programmable, flexible enough to dynamically scale up or down; even the sampling rate can be adjusted dynamically
  • Highly scalable solution with minimal storage requirements
  • Follows the service path, even during topology changes

Quantifying the benefits of active testing

The value of service assurance for mobile backhaul and SLA-backed IP connectivity, two popular use cases for active testing, depends on several factors. These include the number of circuits to be supported, the mean time to repair (MTTR) remotely or on site, and the volume of trouble tickets, particularly repeat ones.

Figure 1: Five simple questions to determine the benefits of Nova Active

Figure 1: Five simple questions to determine the benefits of Nova Active

The Nova Active benefits calculator makes some basic assumptions about the loaded cost of an engineer and a truck roll. It also makes some assumptions about the ratio of remote to on-site trouble tickets.

After filling out the online calculator, you will be presented with the projected savings for different trouble ticket scenarios, as well as total savings over one and three years.

Based on our experience, active testing has significant benefits for service providers. With Nova Active, they regularly see up to a 20% overall reduction (or better) in trouble tickets. When it comes to mean time to repair, we have seen a 50% reduction for remote trouble tickets and a 25% reduction for on-site trouble tickets. And the mix of remote and on-site trouble tickets also sees improvement.

Figure 2: Sample impact on time and cost to repair

Figure 2: Sample impact on time and cost to repair

If you would like to get a more detailed estimate of the savings that you can achieve with Nova Active, you will be asked to provide the following four additional details:

  • Circuit type: business Ethernet or mobile backhaul
  • Actual loaded hourly cost of a network engineer
  • Actual loaded cost of a truck roll
  • Annual cost of SLA violations

Following that, an EXFO account manager will provide you with detailed calculations of ROI, payback and expected savings on SLA violations. The detailed benefits estimate also offers several helpful charts to help you compare your present mode of operations with the proposed future one.