I have a bit of problem. One of my clients regularly get locked out from his LTE provider account and can not recharge it with prepaid home Fixed LTE-A when locked out (password incorrect 3 times). The reason for this is when a person registers for the service you can no longer use GSM/2G/3G. It is pure LTE/LTE-A with no fallback. The OTP to reset the password get MMSed to the sim in the device but it looks like Mikrotik devices can not store MMSes only SMS in the SMS inbox. When I request an OTP the log shows the device is receiving a message but nothing is happening in the inbox.

I did try sending a SMS to the device with a normal prepaid sim and the devices did receive the SMS in the inbox. When I tried to send a MMS to the normal sim it showed it receives a message but nothing in the SMS inbox. Is there a way to make Mikrotik device accept MMSes thru some plugin. This is frustrating due to that the device is high up on tower and every time I have to go up there and take out the sim to put in a phone so I can get OTP MMS.

Sounds like the contract requirements analysis was incomplete.

Requirement: Not to climb up tower needlessly.
sub-requirement: Have MT device accept MMS and SMS.

It is not a contract. He wanted internet that does not require contract so he can mix and mingle his home WiFi packages as he please via prepaid with a provider that is not me. Trust me I am charging him every time I go up there. He just paid me for the devices and I install and configure them for a fee. I don't even know if Mikrotik can even handle MMS messages since I can not find MMS topic in any documentation.

Yeah, I had a look too and couldnt find anything either.

MMS could be entirely OTP service if it didn't use SMS as method to notify user (or rather his phone) about incoming MMS. So while MMS is standard 2.5G+ service it's not something to be implemented in radio chip / modem. At the same time it's not a service of interest for manufacturer of pure data transmission device (such as Mikrotik). And probably isn't supported by USB dongle manufacturer's fancy UI for Windos (those tend do include just everything glittering and shiny).

So I guess the problem of your customer (and hence yours) isn't solvable.

The Wikipedia description https://en.wikipedia.org/wiki/Multimedi ... escription covers the process pretty well.

Automatically handling the SMS control message would be difficult to add to Mikrotiks - if using LTE passthrough there may be no access to the internet for the Mikrotik itself which is required to retrieve the MMS content, for example.

Ideally the carrier should support legacy notification by SMS or email allowing the user to retrieve the content from the providers MMSC, although I'm not sure how they could access it if service is denied due to a locked SIM.

Sim is not locked. It is his login on cellc.co.za that is locked. He can't order LTE-A bundles if he locked out from that account.

Would it not be easier then to make sure the customer stores the correct password somewhere safe? Password manager, encrypted text file, maybe gives it to you in case he forgets? Of course you’ll want to make sure he understands that he cannot try unsuccessfully more than twice. Rather than trying to make the MT do something it likely can’t, remove the human factor from the equation.

That was already done. Unfortunately we are talking about an near elderly person that is very ignorant about tech. It would be good though if Mikrotik can accept mms messages somehow. For I have learned here in South Africa, CellC is not the only network that sends OTP via mms to reset passwords. A lot of home wifi network providers is LTE-A/4G only with no fallback to 3G/GSM. And they always send it to the sim associated with the account in the device via MMS which apparently functions thru LTE and above. SMS only works on GSM over here as i understand it.

And they always send it to the sim associated with the account in the device via MMS which apparently functions thru LTE and above. SMS only works on GSM over here as i understand it.

As already explained, MMS reception doesn't work without working SMS reception. SMS can be delivered in two ways:

1. via CS signalling connection, available on 2G (e.g GSM) and 3G (e.g. UMTS) radio networks, between terminal (phone) and MSC (mobile switching centre, traditional voice switch)
2. via packet service, available on 2.5G (e.g. GPRS/EDGE), 3.5G (HSPA), 4G and 5G radio networks, between terminal (phone) and SGSN/MME/... (packet switching centre signalling gateway, changes name with each generation)

Even though method #2 is available for the last 20+ years, only a few networks implemented it because

1. it requires always-on packet service (PS) which was not really used before 3G
2. it requires additional signalling interfaces implemented in MNO's core network
3. CS signalling, base for option #1, was always there until 3G

With advent of 4G things changed slightly (CS signalling is not there, PS is always on), but vast majority of mobile devices (phones, also data cards) implemented pseudo-CS signalling, needed for voice fall-back to legacy (needed before VoLTE finally took off). But there's no reason for any 4G (and 5G) MNO not to implement delivery of SMSes over PS.


But anyways, since SMS delivery is prerequisite for MMS delivery, choice of MMS for sending "lost password" details is solely cosmetic decission by MNO/ISP ... because MMSes can be nicely formatted, can include graphics, etc. while SMSes can not.