[Android General] Alucard400:
I want to throw in here my assessment of everything I've looked through from the howard forums, xda forums and this particular thread over these years.

AT&T got stringent with flagging smartphones on their medianet/prepaid plans just last year summer.

Known so far:

1. All iphones are flagged, future ones eventually flag.

2. All Nexus phones are flagged,eventually will flag.

3. Most Galaxy phones are flagged (with a few rare ones get around the sweep)

4. Most if not all T-Mobile phones will flag, since the attempted merger.

4. AT&T's IMEI database is updated - AT&T's own sold phones, T mobile phones and a few other carriers. Manufacturers can also share IMEIs such as Samsung, HTC, Apple, etc. to be added to AT&T's database. Not all manufacturers give their IMEI's to AT&T. So far, it seems like Samsung shares most of their IMEIs to AT&T of their latest phones. This applies to international phones. Google also shares all their IMEI Nexus phones. It's not known if Sprint and Verizon share their IMEIs to AT&T.

5. All unlocked phones sold in US domestic retail such as Fry's, Best Buy or other major B&M stores you can walk into should be assumed to be in AT&T's IMEI database.

6. AT&T sold phones are immediately flagged upon inserting and using a SIM card on their smartphones. Non AT&T phones will flag during the billing period or in a day if they are in the IMEI Database.

The list above supercede everything below.

A. Foreign carriers do not share IMEIs to AT&T, such as Telus, Bell Mobilicity, Virgin Mobile Canada, Wind, Fido, etc.

B. Best bet for a phone to get around the sweep would be foreign....Australia, Canada, China, some Euro phones, Japan, Latin America, etc. (Some Canadian phones are flagged though). Good examples of phones not flagged : Xiaomi Mi-One, Meizu MX, Oppo Finder phones.

C. The amount of data used in one billing period does not cause your phone to be flagged as a smartphone, but it could be marked for throttle. Although some users have reported using as much as 20GB and have not been flagged or throttled.

D.LTE inaccessible for medianet and prepaid accounts. only HSDPA.

E. Webpage status of your phone in the OLAM(online account management) do not matter as it's just to determine if the phone is sold by AT&T or not. An htc Amaze by T-mobile will show as unknown just like international phones but will flag during a sweep.

Other possible ways AT&T can flag you for using a smartphone. These are my speculations and may not be true:

-Age/model of SIM card. Some cards are old and only give 3g. some will give faux 4g/HSDPA+. newer cards will have LTE when you use an LTE phone.

-OS type. I remember reading somewhere that windows phones easily flag with AT&T (correct me if I am wrong) because of how the OS is connected on

AT&T's network.

-Flagging or sweeps are different levels. What does this mean? it's possible AT&T sweeps are region specific. The network in the western states could be monthly, while others daily if you're in the midwestern states or in the east. Could be why some people are flagged different periods instead of at the reset of billing period. Some accounts could possibly be tagged to be monitored/checked and flagged after finding out you abuse medianet with a smartphone.

-Type of account you use determines when/how you're monitored- Some people have recently opened accounts with the 3GB data limit. While some may have grandfathered old voice plans. I have the old GSM plan with 5000 night and weekend minutes, cheap monthly. Others still have unlimited night/weekend while some have rollover minutes. Some still have their unlimited data plans.

-Different APN settings may put you in the server that sweeps every month or at different periods.

Other things I have noticed:

Newer phones are manufactured by continent region instead of country specific region. Country specific phones that still get around sweeps: old htc phones. There are old htc phones by T mobile that flag with AT&T, but if you have the Canadian model it will not be flagged because the IMEI is not shared by Telus, Bell Mobilicity, etc. A newer phone such as the HTC One X, HTC One, Samsung Galaxy phones will flag because the phone models are specifically made for north America with LTE. So an AT&T model of the HTC One is the same as an HTC ONE from Canada.

http://xda7.androidrevolution.nl/db_mirror/ROMs/HTC_One/variants.png

I am guessing, an Asia model of the HTC One will work with medianet as it's only HSDPA+ capable without LTE (model 801e. MID:PN0711000). I don't have an Asian model to test this theory. Notice how PN0712000 is made for both USA and Canada as a North American model. There is no Canadian variant of the HTC One. it's the same model as the USA AT&T. Just packaged differently by Carriers in Canada.

I currently use two phones sold in Canada but are variants sold by T mobile USA. These phones have different frequencies and will not work with T-mobile 3g, but work with AT&T hsdpa+ or 3g. They don't flag with AT&T because these are variants made specifically for Canada carriers.

The iphone 5 by verizon didn't flag before. I don't think Verizon shares IMEI's with AT&T, but AT&T was able to get these IMEIs through Apple as they are very close partners. Other carriers(foreign) not sharing IMEIs to AT&T won't matter if the manufacturer gives their database to AT&T. None of the iphones are safe to use on medianet.

International and Canadian Galaxy S phones used to get around the sweeps. Samsung may have shared their IMEI database to AT&T, even with older phones like the Galaxy SII.

edit: more info to add

I had an old HTC phone. the HTC Vision from Bell Canada(first smartphone ever). I used this phone for over a year. placed my medianet account sim into this phone on 2011 around march. I got this phone stolen, then bought another HTC Vision from ebay, took my SIM and placed it into the phone September 2011. I upgraded to the HTC Amaze T-mobile and used it on medianet. I placed my very same SIM into the Amaze on summer 2012 around June. wasn't flagged by the sweeps until August 2012. I did a chat connection to Customer Service to get my medianet plan back and told the rep that I am not using a smartphone. The rep told me I took my sim and placed it on an HTC Amaze, a smartphone. Pretending to be dumb, I told the rep I don't even know what that phone is. The rep then gave the logs when my sim card was placed on phones!!!

Said I placed my sim on the HTC Amaze on

March 2011

September 2011

June 2012

I thought at the time, hm..this rep probably sees the brand HTC on the logs. not the model of the phone. the Amaze I used was really known only because T mobile gave their IMEI database after the failed merger. The rep assumed the march and september 2011 logs were also HTC Amaze but that phone was not even released during that time!

Obviously, those are the dates I placed my sim onto the HTC Vision. But it looks like AT&T can read brands off the unknown model of the phones we use on medianet. probably by the first 8 digits...Which supports the information that kaijura posted below this one(post#1397)

NEW INFO 5/10/2015

I want to add new info. Bedwa has confirmed the APN settings will affect if you get flagged. There are different ways to connect to AT&T with different APN settings. There is one that lets you connect to LTE often. and there are a few where you don't even need the MMS info and another where you don't need the login user/password info. The One I ran with was for connecting to the HSDPA+ (3G signals) constantly.

In addition to the APN info, I can confirm that the Android version you use will also get you flagged. The newest Android versions connect to data in such a way that AT&T can easily flag you. So it's a warning to those who want to update their roms to the newest android for even older phones that work under medianet.

I have already jumped ship and switched to Cricket Wireless. I've already acquired as many as 3 or 4 great phones that worked under the radar but now I am forced to go somewhere else just so I can use the latest roms and Android versions. Plus android wear devices like the Moto360 require minimum Android 4.0 or higher to work. Its been a great run for so many years. But it's just as easy to find a prepaid carrier like Cricket or Straight Talk. The cell towers for medianet accounts are not prioritized, so it is essentially the very same thing when you subscribe data with an AT&T reseller like Straight Talk or Cricket.