When sending SMS from Inreach, sender ID on GSM phone is shown as "MSGREP" instead in satellite phone number form

You are probably going to have to call customer support for a precise answer. If it happens again, I would definitely report it to support as soon as it happens. They will want to know the recipient's phone number and the location of the phone at the time.

Unfortunately, there is a always a third-party SMS gateway that sits between the Garmin servers and the recipient's cell phone provider (and, finally, the recipient's phone). It's the gateway that provides the "from" number that the recipient sees (and replies to) on the phone itself. This is the number from which the gateway sends to message on to the recipient.

In addition to actually delivering the SMS message, the gateway also reports information about the delivery (its "sending number" and the recipient's number) back to Garmin servers. When the recipient replies, the reply goes to the gateway (the number that originated the message seen on the phone). The gateway forwards the message to the Garmin servers. The servers match up the numbers to direct the message to the proper iR device.

Based on what you are seeing on the phone, the fault lies either with the gateway (most likely) or maybe with the recipient's provider (depending on where the message was queued when the phone was unavailable). Garmin will, however, chase it down with the gateway folks if you report it promptly.

The path from iR device to recipient's phone is complicated. Device > Iridium satellite over head > 0 or more relaying Iridium satellites > Iridium ground station > Garmin servers > SMS gateway > recipient's provider > possibly other providers if roaming > recipient's phone. Things get more complicated if the phone is not on the network at the time the message would arrive. Certainly, delays can happen in the Garmin gears. But that's not the only (or most likely) place.

Do note that the number that appears on the recipient's phone is NOT in any sense a satellite phone number. In particular, your iR device does not have a dedicated number. The number on the recipient's phone is randomly assigned by the gateway. It may change from one message to the next.

Thanks, TWolpert! I did some more tests, the problem persists even when the GSM phone is turned on constantly. On Friday I contacted Garmin Slovenia for help and sent them an email with events explanation and data. Today I have also contacted the GSM provider. We shall see.

I will update with news.

Hey Jure,

Do you have any updates on this?

The same happens in Turkey. The SMSs come from "GARMIN" instead of a phone number, therefore un-repliable.

This is an issue with the third-party gateway which serves that location. You should call tech support to find out whether it's a permanent limitation (which IS possible) or a transient problem.

Thanks twolpert,

Which tech support do you recommend? I've been in touch with Garmin support for months now with no success.

Garmin support did not even understand what the issue is, and we are progressing very slow.

Can't help there. Garmin support is regional, so you get different results depending on where you are located. If you have not done so, you might ask them to escalate the ticket.

Hi, it seems that the problem is solved for me in Slovenia. But on the other hand, a new one came out. If more messages are sent to the phone, which is off line at time of transmission, only one comes to the phone, when it is turned on. Other messages are lost. 

cemvedatisik I have sent you a PM to confirm the email address on your inReach account. I'd like to help you with this in any way I can. 

If messages from your inReach are being delivered to SMS phone numbers as being from "GARMIN" instead of a phone number to which the recipient can reply, it is very likely that the carriers are treating the messages as if they are spam or advertisements. We've seen similar issues with cell carriers in different parts of the world and it almost always comes down to changes the carriers need to make to accommodate inReach messages in a way that allows the user to use the inReach in the way it's intended. As twolpert mentioned, this could be a permanent issue with recipients on certain cell providers, however, I'd still like to look into this to get a definite answer for you.