topic Re: FDN Restictions in Other Products and Services

FDN Restictions

Bob_IS_my_Uncle — Fri, 14 Mar 2025 15:48:49 GMT

(Second attempt at posing this question - will be shorter...!)

I've been using FDN successfully for a while (slight vulnerability in letting texts through if RCS chats is activated in Google Messages, but once you overcome that...!)

My question relates to what happens when you change mobile provider. I've done this before with my own phone and having obtained a code from the orignal provider and supplied it to the new supplier, often as not you don't need to change SIM card or anything, you just get a text etc. when the change has been completed...

What happens to FDN restrictions though? From what I can tell, although the list appears on the device itself, it seemed to me as though the restrictions applied 'server side'... Anyone know whether they are 'ported' automatically or whether you need to go set these up again...? Thanks in advance!

Re: Can I limit the numbers available to my child ?

MI5 — Fri, 14 Mar 2025 14:18:21 GMT

Should all be controlled by the list on the device @Bob_IS_my_Uncle

Re: Can I limit the numbers available to my child ?

Bob_IS_my_Uncle — Fri, 14 Mar 2025 16:14:44 GMT

Do you know that or are you speculating...? From what I could see, it appeared as though that's not the case - from the time that I make a change to the list, to the time that it confirms a change has been made, there's typically a few seconds - as though it's updating a server side record and confirming back to the device...

I'll be able to give a more definitive answer in about a month's time after I make the change and test...

Re: FDN Restictions

MI5 — Fri, 14 Mar 2025 16:58:59 GMT

@Bob_IS_my_Uncle

as far as I know it applies the limitations to the sim card, not server, but do let us know what you find.

Re: FDN Restictions

jonsie — Fri, 14 Mar 2025 17:10:03 GMT

If you do change provider you will have to get a new sim card, no choice to be frank

Re: FDN Restictions

MI5 — Fri, 14 Mar 2025 18:05:40 GMT

@Bob_IS_my_Uncle

From Wikipedia:

Fixed Dialing Number (FDN) is a service mode of a GSM mobile phone's SIM card.[1] Numbers are added to the FDN list, and when activated, FDN restricts outgoing calls to only those numbers listed, or to numbers with certain prefixes.[1] A notable exception is that emergency calls to 000, 112, 911, 999 and the like are exempt.[2] Incoming calls are not blocked by FDN.[1]

One practical application of FDN is for parents to restrict the phone numbers their children can dial.[2] The SIM card's PIN2 must be entered beforehand or when applying such settings.[2]