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The IMEI Code: Your phone’s other number

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Re: The IMEI Code: Your phone’s other number

#131

Post by vel0city »

ztetranz wrote: post #92

Fun fact: Lots of cellular modem/routers have the easy ability to change IMEI. Doing so is a fairly common practice in the rural internet community. i.e., those using cellular for their internet access either because cable / fiber or an official cellular option like T-Mobile home internet is unavailable or they're mobile in an RV. These people are not trying to do anything particularly nefarious but they do it so tha…

I remember back in the 00's on AT&T getting an unlimited data plan addon for a dumb phone was like $15/mo or something while adding it for a smartphone was like $40 or more. They would enforce it by checking your IMEI and seeing if it was one of the smartphones they sold.

Buying an unlocked phone of a model AT&T didn't sell seemed to never trigger the "you're using a smartphone" check. Fun times with some cheap 3G back in the day.

Re: The IMEI Code: Your phone’s other number

#132

Post by BayesianDice »

amatecha wrote: post #102
jimbobthrowawy wrote: post #98

Earlier quoted context omitted.

I have heard of people calling emergency numbers to test if a phone is working, but never a country making that impossible. Here, I had always assumed that repeated nuisance callers would be investigated to see if there's an actual problem, and charged with a crime if they're doing it for no good reason. Always thought it would make more sense to have a dedicated "test number" for this purpose. Probably with some rat…

A lot of telcos used to have phone numbers you could call that would just say the number you're calling from (like with a computerized voice). I forget what this was called, but it was talked about in phreaking community or so on. Not sure if these "caller identifier" phone numbers are still around today though.

BT in the UK has 17070 which tells you the number and lets you do tests like the "quiet line test". Handy when working out what was going on when I moved into a property with no live phone service (so no normal outgoing calls), lots of phone extension sockets, and (I discovered) two landlines coming in...

Re: The IMEI Code: Your phone’s other number

#134

Post by eknkc »

If you buy a phone in Turkey, it's IMEI is registered to a gov authority and you can use / transfer it as you wish.

If you happen to buy one from another country, it will be locked after 60 days of use and no carrier will connect it after that. You can use your passport to to prove that it was not imported commercially but you brought it with you and register it. For $1000 (yeah). And it is locked to your ID. Can't transfer it to someone else.

IMEI cloning from an already registered donor phone was a thing and maybe it still is but as far as I can tell, high end phones pretty much lock it tightly.

BTW, this also affects a lot of other stuff. Can't buy a gps dog tracker from amazon. Can't buy a gsm module for your arduiono etc...

My car has a connectivity system where it provides internet to the in car infotainment system and also allows me to open doors etc remotely. It only recently became operational when the distributor finally managed to register the IMEI numbers. A lot of companies do not bother (Mercedes, BMW etc are equipped with similar systems, not operational)

Re: The IMEI Code: Your phone’s other number

#135

Post by londons_explore »

thaumasiotes wrote: post #103
kbolino wrote: post #87

Earlier quoted context omitted.

Assuming something like VoIP is in use, you reach other devices with their IP addresses, not MAC addresses.

As far as I know MAC addresses are never used to route a message to a particular recipient. They're used so that devices that overhear the message, but aren't the intended recipient, can ignore that message on the honor system. If you have a wired connection, this makes the MAC completely superfluous. The concept is sort of still valid for wireless connections (or of course for "wired" connections where you have mult…

Yes - the whole MAC/ARP/IP parts of the typical IP stack are a legacy mess and should be sorted out.

Re: The IMEI Code: Your phone’s other number

#136

Post by sumtechguy »

heilhippo wrote: post #19
BuildTheRobots wrote: post #2

Couple of thoughts > The combination of the ICCID and the IMSI basically tells the mobile network, “hey, this person paid for a plan.” As far as I remember, the ICCID never actually appears in standard network messaging. It might be possible for the network to request it, but it's not part of a standard 2/3/4/5g attach. The piece seemed to miss two major uses for the IMEI (or I missed it when reading), which were wor…

[dead]

The AT commands are usually used at call establish time, but can be used at other times to query the status of the modem. AT commands never go into the network that is a different set of standards. They are only used on the modem in your phone. If you can get on the right serial pin on the modem you can issue AT commands to the modem and it will do all sorts of interesting things. Different companies have their own standards.

Think of the AT commands as just telling the modem to put itself in a particular mode or go do something. After that the serial bits will do different things or output different things. It does not specify what will be said in the data mode (that is the GSM/CDMA/LTE/RS232 standards and a different part of the modem). Just that the modem will do particular things.

Take for example this old command ATDT,,5555555 That tells the modem attention, go into output DMTF sounds, wait 2 seconds, wait 2 seconds, output the DMTF tones on the speaker line for 5555555, then wait for a sound of response on the receiver and negotiate the highest both ends can talk using the S registers to decide what to do. But the AT commands do not go over the wire. They are purely modem commands. The modems in many cell phones still basically do this. But just with different commands and different registers. There is nothing stopping the modem from sending more AT commands to the other side though but that would be something in the standards to declare.

Re: The IMEI Code: Your phone’s other number

#137

Post by grayfaced »

vel0city wrote: post #131
ztetranz wrote: post #92

Fun fact: Lots of cellular modem/routers have the easy ability to change IMEI. Doing so is a fairly common practice in the rural internet community. i.e., those using cellular for their internet access either because cable / fiber or an official cellular option like T-Mobile home internet is unavailable or they're mobile in an RV. These people are not trying to do anything particularly nefarious but they do it so tha…

I remember back in the 00's on AT&T getting an unlimited data plan addon for a dumb phone was like $15/mo or something while adding it for a smartphone was like $40 or more. They would enforce it by checking your IMEI and seeing if it was one of the smartphones they sold. Buying an unlocked phone of a model AT&T didn't sell seemed to never trigger the "you're using a smartphone" check. Fun times with some cheap 3G ba…

In 2004, I was doing something similar on Tmobile. Flip phones internet was cheap. Could tether it via a cable to laptop and I also used an external antenna to improve signal. I would leave it up overnight downloading videos on p2p. I was in Army barracks at time and no one else had decent internet.

Re: The IMEI Code: Your phone’s other number

#138

Post by hiatus »

ztetranz wrote: post #92

Fun fact: Lots of cellular modem/routers have the easy ability to change IMEI. Doing so is a fairly common practice in the rural internet community. i.e., those using cellular for their internet access either because cable / fiber or an official cellular option like T-Mobile home internet is unavailable or they're mobile in an RV. These people are not trying to do anything particularly nefarious but they do it so tha…

What are some of the devices that allow you to easily change the IMEI?

Re: The IMEI Code: Your phone’s other number

#139

Post by vegetablepotpie »

eknkc wrote: post #134

If you buy a phone in Turkey, it's IMEI is registered to a gov authority and you can use / transfer it as you wish. If you happen to buy one from another country, it will be locked after 60 days of use and no carrier will connect it after that. You can use your passport to to prove that it was not imported commercially but you brought it with you and register it. For $1000 (yeah). And it is locked to your ID. Can't t…

> Can't buy a gsm module for your arduiono

What do you mean by that? Ostensibly I can.

https://www.adafruit.com/product/2687

Note: it’s on back order, but in theory I would be able to buy a GSM module for my Arduino.

Re: The IMEI Code: Your phone’s other number

#140

Post by circuit10 »

vegetablepotpie wrote: post #139
eknkc wrote: post #134

If you buy a phone in Turkey, it's IMEI is registered to a gov authority and you can use / transfer it as you wish. If you happen to buy one from another country, it will be locked after 60 days of use and no carrier will connect it after that. You can use your passport to to prove that it was not imported commercially but you brought it with you and register it. For $1000 (yeah). And it is locked to your ID. Can't t…

> Can't buy a gsm module for your arduiono What do you mean by that? Ostensibly I can. https://www.adafruit.com/product/2687 Note: it’s on back order, but in theory I would be able to buy a GSM module for my Arduino.

From reading the message, it wouldn't work in Turkey because the IMEI is blocked
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