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Yuhfhrh

The last few years of Sprint sim cards contained the full CDMA profile, like Verizon sim cards. So without Sprint's policy of required IMEI matching, these sim cards are fully swappable. It's possible Sprint was planning enabling sim swapping at some point. It's been kind of an under the table secret, but many of us have used all kinds of phones on Sprint the last 5 years or so by simply sim swapping. Some phones I used were the Axon 7 and Mi Mix 3 for example (CDMA and LTE!) The secret sauce? If you're rooted, just disable the "sim toolkit" system app on android. Sprint doesn't enforce IMEI matching at the network level, but instead by using an application on the sim card itself that communicates with sim toolkit on IOS and Android. You'll have to set your APN manually of course, and it's best to lock the phone in a CDMA/LTE mode. And no, you can't do this with TNX. T-Mobile enforces the IMEI match on those at the network level, so there are no workarounds.


soulnull8

Fantastic info. I figured the network was booting me off, but it makes sense that it's the phone since you'd think the network would just deny access entirely instead of allowing just to boot. I could probably root, but then again, with Sprint dying, unfortunately the use case is rather limited. Your post makes me realize my shenanigans seem trivial and sorta redundant, but I had fun with it anyways.


Starfox-sf

Sprint really only cares about IMEI when downloading profile onto NV or SIM. Once that is done it’s really Sprint specific firmware bits that is enforcing the IMEI-SIM pairing. 1x/3G does check ESN+profile 1 info to register onto the network because back then you didn’t use SIMs except for intl roaming. LTE checks SIM ICCID, so you can use certain non-Sprint firmware and bypass the IMEI pairing, at least for data. At least that’s been my experience with, ahem, playing with various devices. — Starfox


soulnull8

Excellent information, that would certainly explain why it's *sorta* working but not really. I was thinking this was my excuse to root, but I'm admittedly just having fun tinkering while I wait for my new AT&T sim to fix my data issues. I've been playing with the Sprint sim all day to see what I can make it do. Entertainingly, my sprinternet died a few minutes ago, with bars still showing up, which is not typical of what I've seen today. I went sniffing around, and my APN is back to Verizon, like when I first put in the sim. I've never had Verizon, so..... huh. Interesting little behaviors. I did trigger carrier provisioning in the 4636 screen (not sure what its called), maybe that's why it did it.. but why, with a sprint sim, does it decide to pull Verizon provisioning info? Curious behavior. IMEI now just shows all 0s on the 4636 page mentioned, so clearly I confused the hell out of something. I've had better luck with 1x/3G.. LTE works occasionally, but 3G has been the persistent champ that seems to always work.


temeroso_ivan

I play with it too. Earlier version of Sprint SIM only has LTE profile on it and won't work. Later, especially SIM ICCID starts with 89312530, it has full CDMA profile on it and I have successfully move it to multiple different CDMA phone without phone swap online. However, this is when you are on Sprint Network. Once you are on 311-490, the T-mobile portion of the network will actually match your IMEI with what's on file. If not match, it won't let you connect.


MyAvocation

I can't speak to the R850, but the Franklin T9 is very h*ckable. Can create your own APNs and spoof IMEIs, to name a few. It runs on an old Linux kernel with well known engineering passwords.


soulnull8

I have a T9 from the test drive. That thing is golden. I haven't done much software hacking other than network unlocking, but... Well.. it's being put to good use as my cars hotspot. I glued down the power button and removed the battery so it turns on/off with the car, installed dual mimo antennas on the roof (I'm in a very rural area, it was necessary), and.. well, here's a picture. I like the t9, it's a very useful little box. http://imgur.com/a/CFt49Pp Is it pretty? Hell no.. does it get the job done? Absolutely.


MyAvocation

Awesome! And thanks to the free Testdrive, you can buy more on eBay, etc for a few bucks.


soulnull8

Oh damn, I can't believe I never even thought about that possibility, it's one of those "so obvious it got right past me" things that snuck through my overcomplicating brains blind spot. Absolutely brilliant. I'll have a blast with these. Thanks for the heads up!