topic Re: EE Wi-Fi Calling does not initiate on specific networks (no DNS / no IPSec) in Mobile Services

EE Wi-Fi Calling does not initiate on specific networks (no DNS / no IPSec)

Thomaschui — Fri, 02 Jan 2026 16:28:39 GMT

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Hi EE,

I’m trying to understand a Wi-Fi Calling behaviour specific to EE, which appears to be location / public-IP dependent, rather than a handset or Wi-Fi issue.

Summary

On certain Wi-Fi networks, EE Wi-Fi Calling does not initiate at all:

No DNS queries
No UDP 500 (IKE)
No UDP 4500 (IPSec NAT-T)

This has been verified with packet capture (Wireshark) on both iOS and Android.

The same Wi-Fi network successfully supports Wi-Fi Calling for O2, Vodafone and Three.

Test results

Locations

✅ Reading – EE Wi-Fi Calling works normally
❌ Newbury – EE Wi-Fi Calling never initiates
❌ Bristol – same behaviour as Newbury

Behaviour in Newbury / Bristol

Airplane mode + Wi-Fi: waited 60+ seconds, no Wi-Fi Calling
Attempting to place a call: no Wi-Fi Calling
Packet capture shows:
- No DNS queries
- No IPSec attempt
IPv4 only
DNS tested:
- BT DNS
- Google (8.8.8.8)
- Cloudflare (1.1.1.1)
  → No difference
No captive portal

Controls

Same Wi-Fi, same devices:
- O2 / Vodafone / Three can all establish Wi-Fi Calling
- Works both in airplane mode and normal mode
EE SIM works fine:
- At home
- In Reading
Reading and Newbury have identical local network configuration, only the public IP differs

Devices

EE consumer SIM
iOS 26.1
Android (same result)

Conclusion

This does not appear to be:

a Wi-Fi issue
a DNS issue
a handset or OS issue

It looks like EE Wi-Fi Calling is being prevented from initiating by an internal pre-check / policy decision, likely based on public IP / routing / location, as the client does not even start the DNS or IPSec phase.

Question

Can this be reviewed or escalated to the EE network / IMS / Wi-Fi Calling team to confirm whether this behaviour is expected or configurable?

I’m happy to provide further technical details if needed.

Thanks.

Re: EE Wi-Fi Calling does not initiate on specific networks (no DNS / no IPSec)

XRaySpeX — Fri, 02 Jan 2026 23:47:51 GMT

Who is the BB provider in the 3 locations? Using which router?

Re: EE Wi-Fi Calling does not initiate on specific networks (no DNS / no IPSec)

Thomaschui — Sat, 03 Jan 2026 00:12:49 GMT

All locations are using BT 500 Mbps leased lines, and the router in use is a TP-Link ER8411.

The key point is that the same router model, firmware and configuration is used in Reading and Newbury.

• Reading: EE Wi-Fi Calling works normally
• Newbury / Bristol: EE Wi-Fi Calling does not initiate at all

The only difference between these sites is the public IP / routing provided by the BT leased line, not the local router, firewall or Wi-Fi configuration.

On the same ER8411 router and Wi-Fi network, Wi-Fi Calling works immediately with O2, Vodafone and Three SIMs, both in and out of airplane mode.

Packet capture confirms that in Newbury/Bristol the EE Wi-Fi Calling client does not even begin DNS resolution or IPSec negotiation, which suggests a decision made before Wi-Fi Calling setup, rather than traffic being blocked by the router or ISP.

If EE Wi-Fi Calling has any specific requirements or exclusions related to leased-line IP ranges, routing, MTU, or NAT behaviour, I’m happy to validate those – but based on the identical setup comparison, this appears to be EE-specific behaviour.

Re: EE Wi-Fi Calling does not initiate on specific networks (no DNS / no IPSec)

Thomaschui — Wed, 07 Jan 2026 10:51:57 GMT

Is it possible for this to be escalated to an EE network or IMS engineer who can review the findings and help determine the root cause?

I’m happy to provide packet capture evidence or any additional technical details required.

Re: EE Wi-Fi Calling does not initiate on specific networks (no DNS / no IPSec)

Rach_H — Wed, 07 Jan 2026 14:37:41 GMT

Hi @Thomaschui,

Welcome to the Community!

Im sorry to hear about the trouble you've been having. The best way to get this escalated would be to give our team a call, and the team will be able to look into what is happening with your calls.

Rach

Re: EE Wi-Fi Calling does not initiate on specific networks (no DNS / no IPSec)

XRaySpeX — Wed, 07 Jan 2026 14:45:34 GMT

I can't believe that a phone, designed for nationwide, if not worldwide use, would have diff behaviour, in the same environment, in Reading from the rest of S. England.

Re: EE Wi-Fi Calling does not initiate on specific networks (no DNS / no IPSec)

Andy_65 — Wed, 07 Jan 2026 15:41:48 GMT

@XRaySpeX There's been a few similar threads recently, today I'm 15 miles from home and WiFi calling will not show as working for me. This is on Sky FTTP WiFi, I have no problem at home with EE broadband. Unless something has changed in ios where WiFi calling doesn't show if there's sufficient signal strength (which I doubt), then it would seem to me that something is going on.