When the Network Fails: How 2025 Telecom Outages Broke “Healthy” Applications
The major telecom outages of 2025 revealed a blind spot many reliability teams still have: applications can fail even when internal systems look healthy.
In 2025, UK telecom outages made one thing clear for reliability teams: your application can be healthy while the network to your users is not. When carrier voice services failed on June 25 and again on July 24–25, customers couldn’t place calls, and some disruption affected access to emergency services. The UK regulator Ofcom later opened formal investigations into those outages.
For SREs and infrastructure leaders, the lesson goes beyond telecom. Users reach your app through networks you don’t control, and most observability still stops at the cloud edge. When routing, DNS, or a carrier segment breaks upstream, dashboards can stay green while users see login failures, timeouts, and dropped sessions.
This article explains why these failures are so hard to diagnose, what signals help you spot an external network issue early, and how to model external dependencies so cause and impact are clear across regions.
2025 Proved the Network Can Be the Failure Domain
In 2025, the UK got a sharp reminder that a carrier outage can become everyone’s outage. When national networks stumble, it’s not treated like routine downtime. It’s treated like critical infrastructure failure, and regulators respond accordingly.
UK telecom outages weren’t “just carrier issues”
Two incidents made the point:
- June 25, 2025: According to Ofcom, an incident caused a UK-wide disruption to call services on Three, including customers’ ability to contact emergency services. (Ofcom investigation)
- July 24–25, 2025: According to Ofcom, a software issue caused a UK-wide disruption to mobile call services interconnecting to and from the EE network (Ofcom investigation), affecting calls to other networks and emergency services.
And this didn’t end with an apology. According to Reuters, Ofcom opened formal investigations to assess whether safeguards and mitigations were adequate.
If you run services that depend on mobile access, those details matter. Your customer doesn’t experience “carrier trouble.” They experience a failed login, a dropped session, or a stalled checkout.
Why enterprise teams should treat this as operational risk
Your uptime is now tied to systems you don’t own: carrier cores, routing decisions, DNS resolvers, peering points, and CDN edges. When any of those layers degrade, users can’t reach you even if your stack is fine.
And most teams still have a visibility problem: monitoring usually stops at your environment boundary. The routes and name lookups your users rely on stay invisible until support tickets and social posts tell you something is wrong.
Your Dashboards Can Be Green While Applications Fail
Some of the hardest incidents start the same way: users are blocked, but your metrics look normal. Logins fail. Sessions drop. Pages hang. Checkout times out. Meanwhile, SLO charts stay steady.
That’s what happens when the problem sits before a request ever reaches your systems.
Where the failure often sits
It’s easy to trust green dashboards because they reflect what you control. But many user-visible failures happen upstream:
- DNS can’t resolve your domain reliably
- Routes change and traffic detours into congestion
- A carrier interconnect issue blocks calls, authentication flows, or OTP delivery
- An edge path breaks in one geography while everything else looks fine
A common 2025 pattern: user failures, steady dashboards
On July 14, 2025, Cloudflare’s 1.1.1.1 public DNS resolver had 62 minutes of downtime after a change to service topology caused an outage on the edge, per Cloudflare’s incident report. (Cloudflare postmortem)
For companies configured to use 1.1.1.1, DNS lookups failed, so apps looked “down” even when cloud regions and services were operating normally.
You can’t fix a DNS outage with a restart. You can’t scale your way out of a routing withdrawal. But without visibility into those external layers, teams often burn an hour trying anyway.
Why This Isn’t Only a Telecom Problem
Even if you never touch carrier infrastructure, your service still depends on networks you don’t control. The more regions you serve, the more often this shows up.
The parts of delivery you don’t own
When something breaks between the user and your cloud edge, the incident turns into a blame carousel. Everyone has a plausible theory, and nobody has proof:
- “It’s probably the ISP.”
- “The CDN looks fine from here.”
- “DNS is acting weird.”
- “The region is healthy, so it must be the app.”
- “It only happens in one geography.”
Meanwhile, user traffic may be crossing any combination of:
- Local ISP routing shifts that change the path without warning
- Regional carrier congestion that forces detours and adds latency
- Internet exchange and peering issues that flap sessions
- DNS resolution failures that make logins hang or time out
- CDN edge differences where one location hits a bad path
- Cloud backbone routing changes that spike cross-region latency
None of this shows up clearly in typical APM traces, logs, or host metrics. Yet any one of these layers can stop a basic user workflow.
Routes can change in minutes, and the symptom looks random: “only some users,” “only one region,” “only on mobile.” You still have to explain impact to customers and leadership. Sometimes you also have to explain it to auditors. At that point, network reliability becomes business risk: downtime, longer war rooms, missed SLAs, and damaged trust.
Where Traditional Observability Breaks Down During Network Outages
Most observability stacks are built to explain what happens inside your environment. They struggle when the slowdown happens between the user and the cloud edge.
Why internal signals don’t explain external failures
Logs, traces, and infrastructure metrics assume a simple rule: if internal signals are clean, the service is fine. But user experience depends on the whole path: ISP → carrier → DNS → CDN → cloud edge → your service.
When that path degrades upstream, internal dashboards can stay clean while users fail.
In 2025, routing and DNS failures created real user outages
You saw the pattern repeatedly: a change upstream breaks reachability, users feel it first, and internal telemetry can’t tell you why. Cloudflare’s July 14 DNS incident is a clean example because the root cause and timeline were published.
The takeaway is practical: when you can’t see external path health, incidents last longer, the wrong teams get pulled in first, and war rooms churn. Faster resolution starts with the ability to answer one question early: is the failure inside our stack or on the network path to the user?
What IT Leaders Should Change Operationally
Better incident response is less about heroics and more about early, repeatable decisions. Your goal is to identify the failure domain quickly and communicate clearly.
Make external network investigation an early incident step
Don’t wait for internal error rates to spike. External failures can block users without triggering obvious application alarms. Treat routing, DNS, and carrier health as first-hour checks, not last-hour checks.
Model the full user path, not just the service stack
Your architecture diagram is not the same thing as the path users take at runtime. Build an operational model of the end-to-end path by region. When an incident hits, you’ll know what to check and who to engage.
Be ready to prove impact and mitigation
Regulators are scrutinizing national outage response. According to Reuters, Ofcom’s investigations focus on whether adequate safeguards and mitigations were in place. Your customers are asking harder questions too, even when the failure wasn’t “in your code.”
How WanAware Brings External Dependencies Into View
Once you can see the end-to-end path, incidents stop feeling mysterious. Teams move from guessing to evidence.
Map the paths users actually take to reach your services
WanAware connects the real delivery path across ISPs, carriers, DNS, CDNs, and cloud edges, so you can see how users reach you by region, not how you hoped they would.
Identify whether the failure is inside your stack or on the network
When customers report failures but app telemetry stays clean, WanAware helps you decide quickly whether the problem lives on the network path. That reduces unhelpful restarts, avoids unnecessary escalations, and gets the right owner engaged sooner.
Communicate impact and next steps with evidence
WanAware helps you report what’s affected, where, and why. Instead of “we’re investigating,” you can say: which regions are impacted, which upstream segment is degraded, and what mitigation options are available. That improves customer comms, SLA conversations, and post-incident reviews.
Conclusion: Treat the Network as Part of Reliability
Reliability is not only what you run. It’s also what users must pass through to reach you.
The takeaway from 2025: failures can sit outside your stack
In 2025, some of the most damaging outages weren’t caused by application code or cloud capacity. They were caused by upstream network and routing layers that most teams don’t instrument day to day.
If you want fewer ghost incidents, you need visibility into the path, not just the service.
The advantage: faster diagnosis, less war-room churn, clearer comms
Teams that can see beyond their own walls resolve incidents faster, pull in fewer people unnecessarily, and communicate with confidence. Teams that can’t will keep spending cycles proving what they don’t control.
WanAware brings the network into the reliability equation. Because in 2025, some of the biggest failures weren’t inside the system. They were outside of it.
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