CellC WiFi calling not working?


Mar 22, 2012

I am currently out of SA and probably won't be back before next year given the way that things are going. Myself and my wife are on CellC and have been using WiFi calling since we got here, but it seems to have stopped working around the beginning of March.

I've been using my device (iPhone X) as it's supported, but it won't register on the network anymore. I captured the network traffic from my phone and it looks like the IPsec tunnel negotiation fails for some reason (server sends back INVALID_IKE_SPI and terminates the connection).

- I've contacted CellC and they say that WiFi calling should work (no issues they know of)
- The sim cards are still valid (last chargeable call was made late Feb, confirmed by call center consultant)
- I've tried with various VPNs in case it was a network issue, both one in South Africa (Nord) and one in Germany (private VPN, this one worked before with WiFi calling) with no luck. Running on the router, so wifi traffic was forced through the VPNs

While we both would like to use WiFi calling, another issue is that our sim cards will expire at the end of May and we'll lose our numbers if this isn't resolved. The interim plan will be to upgrade to some cheap contract, but ideally I'd like to get this sorted. As usual, it's really difficult to talk to someone who knows what IPsec is, why it's part of WiFi calling, and how to look at a pcap file so I'm reaching out here.

If anyone from CellC (or anywhere else really) is able to help, let me know and I can send you the capture or help with debugging. I'd be really happy if this could be resolved! TIA


Cell C Representative
Company Rep
Sep 7, 2010
Hello Michael

May you please us your query + your Cell C and contact number?

We will get our Technical Team to look into it.