The telecom industry is currently placing all its bets on Full Fibre (FTTH/FTTP). We promote the idea of “lightning-fast speeds” and “lag-free gaming.” However, a troubling misconception is taking root in the ISP community: the belief that once a customer is connected to fiber, the work is complete.
The truth? Fiber is not a cure-all for customer satisfaction.
Even if you have addressed the “last mile” bottleneck, a new, unseen battleground has surfaced further within the network. Nowadays, customer loyalty is not achieved through marketing gigabit speeds; it is earned through the genuine experience subscribers encounter daily across the applications they depend on.
The New Bottleneck: OLT to BNG
In a conventional copper or hybrid network, the main bottleneck was typically the wire that enters the home. In a Full Fibre network, that pipe is massive. This change shifts the pressure upstream, particularly to the segment that lies between the Optical Line Terminal (OLT) and the Broadband Network Gateway (BNG).
Why is this particular segment experiencing choking?
The issue boils down to the volume and type of content. It is evident that video traffic is surging, making up over 74 percent of mobile data traffic by the end of 2024 – a pattern that is also seen in fixed broadband. Streaming powerhouses such as YouTube, Netflix, and Disney+ now dominate the broadband infrastructure.
When an entire neighborhood decides to hit “play” in the evening to view high-definition content, the aggregation link connecting the OLT (which collects traffic from hundreds of homes) and the BNG (which directs that traffic) becomes a bottleneck.
Speed Tests Lie, Experience Doesn’t
This congestion presents a paradox. When a customer conducts a speed test, they may observe high throughput figures since speed tests utilize aggressive multi-threaded downloads that fully utilize the link. However, the streaming video, gaming, video conferencing, voice over IP, and other content and applications they rely on, which depend on delicate, single-threaded bit streams, could be facing issues.
This is where conventional network monitoring techniques are inadequate. An operator might view a dashboard displaying average KPIs over several minutes and see a green screen, yet the customer is facing:
- Long start times for their movies.
- Lagging gaming experience.
- Poor voice quality on their voice-over-IP calls
If you depend only on traditional SNMP network counters, you are operating without visibility. You are assessing the capacity, not the actual flow of data.
The Importance of Active Monitoring
To protect the OLT-BNG link, operators need to go beyond mere passive monitoring and embrace Active Monitoring. This means introducing synthetic traffic that replicates genuine user activity to test the route from the customer premises (or the OLT) to the core.
By actively recreating these user experiences, you can identify micro-congestions in the aggregation layer before a customer has a chance to lodge a complaint.
Why You Need MOS (Mean Opinion Score)
How can you quantify this active data? You don’t rely on bits and bytes; you utilize the Mean Opinion Score (MOS).
MOS converts complex technical metrics into an easy-to-understand, human-focused score ranging from 1 (bad) to 5 (excellent). It serves as the most practical measure of user satisfaction available because it:
- Models actual human perception rather than just raw network statistics.
- Considers the complexity of modern delivery, including how adaptive bitrate (ABR) algorithms react to network changes.
- Holistically combines factors like initial loading delay, packet loss, jitter, and delays into a single truth
Value Propositions: The Importance for Fiber Operators
If you are deploying full fiber, here’s why you should change your monitoring approach:
- Protect Your Premium Price Point: You cannot justify high prices for fiber if the Netflix experience resembles DSL. Active monitoring guarantees that the network’s performance aligns with the cost.
- Reduce “No Fault Found” Truck Rolls: When customers report buffering issues, but your passive tools indicate everything is fine, you dispatch a technician who finds no problems. Active monitoring uncovers hidden congestion between OLT and BNG, reducing operational costs.
- Predict Churn Before It Occurs: Network performance influences nearly 40% of customer switching decisions. By focusing on QoE (Quality of Experience) instead of merely passive network KPIs, you can pinpoint customers at risk of leaving before they decide to cancel.
The Conclusion
For the past twenty years, we have designed networks to be measurable. The upcoming decade of fiber will focus on engineering networks to be felt.