question regarding a mobile phone overseas without roaming

[Grooba]

All my instinct tells me this is a silly question and I know the answer but I'm after clarification from the brains trust.

I had a question asked of me the other day, if you go overseas with a mobile that does not have roaming and someone calls the number, does the caller hear the "international beep beep beep" before it would normally ring? Or because the phone does not have roaming enabled, all the caller would hear is the same as if the phone was switched off (like straight to voice mail without the "international beep beep beep")?

My first reply was that the caller would not know the phone was overseas but I'm not 100% convinced.

 

[drewbles]

When you turn on your mobile overseas, it searches for what's known as the VLR on a network (The Visitor Locator Register). When a roaming agreement between providers is put in place, your home telco shares your SIM ID (the ICCID) with the roaming partner, and allows it to roam. If it's not on the VLR, the telco will not let you register to a network. No registration = phone off (for all intents and purposes).

So, if you have no roaming, and attempt to register overseas, it'll fail, and anyone calling would get your voicemail or 'the person you are trying to call is unavailable' etc.

 

[Grooba]

Awesome thanks drewbles it's great to understand the technical aspects of how this works, much appreciated.

 

[drewbles]

Awesome thanks drewbles it's great to understand the technical aspects of how this works, much appreciated.

I could go 'in depth' on this, but it's seriously boring

 

[marki]

I could go 'in depth' on this, but it's seriously boring

This stuff is interesting drewbles. Not all that boring

 

[drewbles]

This stuff is interesting drewbles. Not all that boring

I guess when it's a large part of your 9-5 routine it can get boring at times