Friday 7 June 2019

OnePlus 7 Pro How to Enable Hidden VoLTE and VoWiFi Menus

OnePlus 7 Pro How to Enable Hidden VoLTE and VoWiFi

Here in the UK, I've been aware that my mobile phone provider, Vodafone, supports Voice over 4G (VoLTE) and also Voice over WiFi (VoWiFi).

Both of these technologies are interesting because they allow you to call on your mobile in different ways.

A solution for Vodafone UK customers was to buy a Vodafone Sure Signal. These are interesting devices because they use a little bit of your broadband bandwidth to mostly fill your home with a 3G signal. As great as that seems, there are a few problems however:
  1. They run bloody hot
  2. You have to register each Vodafone number one by one to allow them to be recognised
  3. If you have used a PAC to port your old mobile number from another network, the online MyVodafone app will usually tell you that this is not a Vodafone number. To be fair, a call to Vodafone can normally fix this as long as you wait a few hours
  4. If you have a problem, a call to Vodafone gets you the help of a low paid helpdesk person who is just reading from a script.  After trying to explain your problem, they invariably come back with the "I've reset it and it could take up to 6 hours to come back online"
  5. They are quite expensive, especially as you are buying them for the sole reason to use the mobile phone network you are already paying for....


4G does not carry voice communications natively; it is just a higher speed data service. On a normal 4G mobile when you either place or receive a phone call, the phone will switch out of 4G and drop back into 3G. Have you ever noticed your signal level change when you are on a call? This is because your mobile changes to a different mode and quite possibly a different frequency when a call is initiated.

In the past this was significant because there were fewer 4G capable mobile phone masks than there were 3G masks. In fact during a call you would find the signal level jumping a few bars higher. Additionally, since 4G (or LTE as it's also known) is on a completely different frequency, this can be a big factor too.

Nowadays signal strength is not too significant because most celular masks are now all 4G capable. However, as 4G is a higher bandwidth than 3G, it makes sense to add VOIP capabilities to a 4G cell; this is termed VoLTE.

Since the Operating System of Apple phones is stable and the same, if you are an owner of one of these devices you can hunt through the menus and enable VoLTE there.

Android, however, has many different flavours and most providers have not got round to certifying the many different handsets - therefore VoLTE is probably missing. Frustratingly the OnePlus 7 Pro (and most others) fall into this category. But don't worry, if you're brave you can switch it on! 😁


If you're in the countryside or even have a house constructed using modern insulation, you probably get a somewhat sketchy signal indoors. Generally, the quality of the voice reception can cut in and out. Fear not, you can switch your phone to allow Voice over WiFi and still use your phone as if you lived next door to a mobile phone mast even if you have no signal.

The same situation arises like above, you should be OK if you've got an Apple phone but an Android phone usually needs to have been bought from the mobile operator themselves.

However, you can switch-on WiFi calling in your Oneplus 7 Pro... hoorah! 😊

A chap on another forum explained all this as:
Simon Farnsworth says:
If VoWiFi works, and the handset does VoLTE on networks that support it, you want to turn VoLTE on, too - assuming that the handset and network actually implement the standards properly, support for VoLTE will give you seamless call hand-off between WiFi and 4G (LTE) mobile networks, plus calling on 4G with seamless fallback to 3G/2G as appropriate (and fall-forward to 4G when in coverage), plus audibly glitchy handoff between WiFi and 3G/2G networks.
On its own, this gives you better chances of sustaining a voice call; further, there's optional components to the spec that, if implemented at both ends, will give you seamless handoff between WiFi and 3G networks for voice calls, meaning that you can keep a voice call going until you lose coverage.
For the nerds among us; VoWiFi and VoLTE are the same thing on different radio networks (both are SIP + RTP talking to the network operator's IMS service). In VoLTE, the IP packets are carried over LTE directly to your network; in VoWiFi, your phone establishes an IPSec tunnel to a well-known DNS name (, where XXX is the three digit MNC, add a leading zero if you have a 2 digit MNC like 30, and YYY is the MCC, such as 234 for the UK).
There's specified handovers to cleanly (no glitches) hand over the IP packets between radio types, and to switch from IP to circuit-switched voice if on the mobile network. There's also specified hand overs for IP to circuit-switched if not carrying IP over the mobile network (which are allowed to glitch), and an optional spec for carrying the IP packets over UMTS/HSPA instead of LTE.

Secret Sauce

There are a lot of of discussions about enabling VoLTE and VoWiFi over the internet but when you dial *#800# to access the secret OnePlus Logkit program menu on your OnePlus 7 Pro, excitement soon turns to disappointment when after navigating the menus, lands you to the set-up page where VoLTE and VoWiFi are not there.

After having thoughts about going through the pain of rooting my brand new phone, I came across this site here. You need to replace the factory supplied Logkit with a new version - it's actually called

The good news is, this is very easy. Just head on down to