Dual Sim phones and 2G switch off

Kosmik

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So for general discussion, I've been using a Huawei P Smart for a while now and have the dual sim functionality enabled with a Rain sim in the second slot. This works perfectly as I still get my calls etc. on the primary and can burst into pay as you us with Rain vs being forced to buy bundles etc. with limited span, especially as it only happens on occasions and I normally need a little top-up as am mostly in Wi-Fi.

For the first time in a while, I needed to use my data quite extensively so it gobbled up my primary sim, switched over to the Rain for data and kept on running. About a day or so later I noticed some issues where I wasn't getting some SMS ( Microsoft OTP ) which I put down to international issues but then on Tuesday I had a delivery due but never received any contact. Checking my phone, no calls and no SMS.

For the last year I've been heavily teams based and the family also uses WhatsApp calls etc. so actual phone usage has been low. To ty trouble shoot, I switched data back to my primary sim and lo, suddenly I got inundated with a few missing SMS and notifications of missed calls. Unpacking further, I looked at the dual sim setting screen. I noticed that when you enable data mode on the second sim, it switches the first sim to 2G only and the second sim has 2G/3G/4G enabled.

Screenshot_20210625_124353_com.huawei.android.dsdscardmanager.jpg

Screenshot_20210625_124420_com.huawei.android.dsdscardmanager.jpg

My only thought is that with the supposed shutdown of the 2G network, when the phone is switched over to the second sim, the first sim is no longer able to communicate with the tower as this was being done over 2G before. Anyone else experienced this? Am I off base? If I'm right, this kills a lot of dual sim phones from being usable.

@Jan maybe worth an article, this is on the Telkom network.
 
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backstreetboy

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Lol, actually I prefer google authenticator which I have a ton but didn't see the option for MS, they want their own.
Strange I only know of Steam and Battle.net that force their own apps and I had to use a third party tool to get the codes into Bitwarden.
 

warwickw

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Back to OP's original issue.

I tested now putting a Telkom Mobile sim in an old Nokia 2G phone, which I know used to work. It no longer can connect to a tower just stays on emergency use only.

Think Telkom Mobile may have stopped 2G in some areas.
 

CranialBlaze

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Did not know they had already begun shutting down GSM, wonder what calls are running on them, this is SA after all, there are probably but loads of GSM only phones still in active use.
 

Kosmik

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Did not know they had already begun shutting down GSM, wonder what calls are running on them, this is SA after all, there are probably but loads of GSM only phones still in active use.
Yes, all the stuff I read spoke about 2024.
 

c3n0byt3

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@Kosmik your theory may or may not be correct.
However I can say that on my P30 both sims have 2G/3G/4G (Telkom + CellC) regardless of which one is primary.
But I do notice you have the "default calling SIM" set. I have mine as "not set" (it's an option). Maybe try that?
When you make a call or sms, are you given the option of which SIM to use?
 

Kosmik

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@Kosmik your theory may or may not be correct.
However I can say that on my P30 both sims have 2G/3G/4G (Telkom + CellC) regardless of which one is primary.
But I do notice you have the "default calling SIM" set. I have mine as "not set" (it's an option). Maybe try that?
When you make a call or sms, are you given the option of which SIM to use?

Its not so much the calling out, the fact that I can't receive is the problem. The thing is, had the phone this way since 2018 I think, so its really not a settings thing.
 

Burrrrrton

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A good question is how old is your smartphone. It's just that modern dual-sim support 4G on both SIM cards.
 

nashuasa

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Go to network settings and manually select vodacom on 2G, that works when there's no Telkom Mobile coverage
 

Kosmik

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Go to network settings and manually select vodacom on 2G, that works when there's no Telkom Mobile coverage
I'll try that if it happens again.

I noticed that down the road at another tower edge worked fine so its probably tower kit dependant.
 
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