I've been digging into eSIM infrastructure lately, and the more I look, the more I realize most people have no idea what happens after they activate a plan.
The marketing is simple: "Local data in 190+ countries." You'd assume that means local infrastructure. Connect in Germany, get a German IP, traffic routes through German carriers.
Often that's not what happens.
How eSIM routing actually works
When you buy an eSIM, you're not getting a direct relationship with a local carrier. You're buying access through a chain of intermediaries.
Here's the typical architecture:
Your Device
↓
eSIM Profile (downloaded via SM-DP+)
↓
Aggregator's Network Hub
↓
Wholesale Carrier Agreement
↓
Local Radio Access (the actual cell tower)
↓
Internet Breakout Point ← This is where it gets interesting
That last part — the internet breakout point — determines where your traffic actually emerges. And it's often not where you are.
Local breakout vs. hub routing
There are two main approaches providers use:
Local breakout: Your traffic exits to the internet in the country you're connected. You get a local IP, local latency, everything behaves as expected.
Hub routing: Your traffic routes back through a central hub - often in the Netherlands, Luxembourg, Singapore, or wherever the aggregator's infrastructure sits. You're "connected" in Germany, but your IP says Amsterdam.
Why hub routing? It's cheaper and simpler to manage. The aggregator maintains one internet exchange point instead of dozens. Most users never notice.
How to check where your traffic actually goes
If you're curious about your own connection, here's how to verify:
Check your public IP:
curl -s ifconfig.me
# or
curl -s ipinfo.io
Get detailed geolocation:
curl -s ipinfo.io/json | jq '{ip, city, region, country, org}'
Trace the route:
traceroute 8.8.8.8
# or on Windows
tracert 8.8.8.8
If you're physically in Germany but ipinfo.io says Netherlands, you've got hub routing.
Compare with expected location:
# Your device's timezone
date +%Z
# vs your IP's reported location
curl -s ipinfo.io/timezone
A mismatch here is the classic sign of hub routing.
Why does this matter?
For basic browsing, it probably doesn't. Your Instagram loads, email works, life goes on.
But for certain use cases, routing matters more than providers admit:
Latency - Hub routing adds distance. A connection that routes from Frankfurt → Amsterdam → Internet adds 10-20ms minimum. For video calls or real-time apps, you'll feel it.
Platform trust - Banking apps, streaming services, and social platforms check for consistency. If your IP says Netherlands but your timezone says Germany, some services flag that as suspicious. I've had login prompts triggered purely because of this mismatch.
Jurisdiction - Your traffic passing through a country subjects it to that country's legal framework. If you care about privacy, knowing which jurisdictions your data transits matters.
Content access - Some region-locked content checks IP location, not just account region. Hub routing can put you in the wrong bucket.
What providers actually do
I looked at several major eSIM providers. The transparency varies wildly.
Most consumer providers (Airalo, Holafly, and many others - actually most of companies, they don't publish routing details. Their documentation covers countries and speeds, not infrastructure. I've asked support directly and gotten generic "local carrier partnerships" responses. Not malicious, just not helpful.
Some bundle workarounds: Saily, backed by Nord Security, includes a Virtual Location feature with their plans. They don't publish routing details either, but this feature lets you control your apparent location anyway. It's solving the problem sideways.
A few are transparent: VoidMob publishes routing details and is upfront about where traffic terminates. They've written about why this matters in more depth. Smaller player, but refreshing approach.
The pattern: bigger consumer-focused providers optimize for coverage marketing. Infrastructure transparency isn't a priority because most customers never ask.
Why providers don't talk about this
Having looked into this more, I get why it's not discussed:
It's genuinely complex. Routing depends on carrier agreements, aggregator relationships, even time of day and network load. Documenting it accurately is hard.
It changes. Providers switch aggregators, renegotiate deals, add new carrier partnerships. Publishing details means maintaining them.
Competitive reasons. Routing infrastructure is part of the product. Publishing your setup means competitors can see it.
Most users don't care. The average vacation traveler wants data that works. "Where does my traffic route?" isn't a common question.
I'm not saying these are good excuses. But they explain the industry-wide silence.
The technical reality
If you want to understand this deeper, here's what's actually happening:
eSIM profiles are provisioned via SM-DP+ (Subscription Manager — Data Preparation). The profile contains authentication credentials for the carrier network, but doesn't dictate routing.
Routing decisions happen at the aggregator level. Companies like BICS, Tata Communications, and others run the wholesale networks that connect eSIM providers to local carriers. They decide where traffic breaks out to the internet.
Local carrier breakout requires agreements with each carrier in each country — expensive and complex. Hub routing is simpler: all traffic comes back to a central point, regardless of where the radio connection is.
The GSMA's eSIM specifications cover the profile and provisioning standards, but say nothing about routing. That's entirely up to the provider and their aggregator partners.
What you can do
If routing matters for your use case:
Ask before buying. "Where does traffic terminate when I connect in [country]?" If they can't answer, that tells you something.
Test with the commands above. Get data, don't assume.
Consider VPN bundled options. If the provider won't give you routing transparency, a VPN gives you location control regardless.
Check provider documentation. The rare few who publish routing info deserve credit for it.
For most people, eSIM just works and routing doesn't matter. But if you're using it for work, accessing sensitive services, or just want to understand what you're buying — now you know where to look.
I wrote more about why providers don't share this information if you want the full backstory.
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