LineLink doesn't work with T-Mobile 5G home internet router

  • 30 April 2021
  • 8 replies


I was going to post my comment here:


But comments are closed on that one, so I’m starting a new thread.  I’m having exactly the same issue described in the link above.  In short, after weeks of calling, each time promised a call back from an expert that never came (waiting on one right now), my LineLink home phone line will not connect.  I was told the same thing mentioned in the link above, that the 5G nokia router is not compatible with the LineLink device.  However, I’ve also been told several other things from different T-Mobile reps:

  1. Billing department says it should work fine… they forward me to tech support.
  2. LineLink tech support checked my sim card, device status lights, and said it should be working fine… forwarded me to the home internet tech support.
  3. Home internet tech support first didn’t understand the problem.  They first said there was a tower upgrade in the area causing problems, which doesn’t make sense because I’m getting internet just fine, only LineLink doesn’t work.  They then put me on hold and said that there is an existing ticket in their system suggesting that the LineLink device is not compatible with their 5G internet router… said they’d call back in 3 business days to let me know the status (that was 9 days ago).
  4. Now I’ve been told that my sim card needs to be replaced… So now I need to wait for that.

All in all, I’ve been calling for over a month.  Honestly it feels like they are just throwing things around to see what sticks.  I have some ideas of my own in case someone from T-mobile actually reads these things.

Hypothesis #1: When I switched from comcast to T-mobile for my ISP, the device is now seen by T-Mobile as coming from a different IP address, which will make it appear that I have moved it to a new location.  I suspect that all that needs to happen is that they need to reset it on their end so that it’s registered to the new IP.

Hypothesis #2: The T-mobile router is blocking some port that the LineLink needs to operate.

Hypothesis #3: Since according to their own page ( LineLink is no longer sold by T-mobile, they have simply stopped caring about supporting it.

Could be any combination of those.

8 replies


Update: As a test I was able to connect the LineLink to my computer and share my internet connection to it that way, and connect the computer to my phone’s wifi hotspot, and that DID work.  So that rules out any problem with the SIM card.  But it still doesn’t work when connected to my T-mobile home internet router, which is what I really need.

That said, I spoke to another T-mobile support person, and got a little more definitive information.  They said that there is a known incompatibility between the LineLink and the 5G home internet router devices.  Further, that this was not going to be fixed any time soon, and they recommended that I port my LineLink number to another provider.

I still think it’s got to be something simple like needing to open up a port on the router or something, but from the sound of it, this won’t be looked into for a while.  Perhaps weeks, he said.  Therefore I’m going to switch back to Vonage (which is what I was on before). 

I also just want to state, for the record, that the T-mobile support folks have been excellent and very helpful.  I believe the problem that I had being bounced around between departments is a systematic problem between their 3rd party support company and their main support, specifically with documentation and training perhaps, and just being overloaded and not being able to handle the capacity.  But the people themselves are great, both with the main support folks and the 3rd party support company.  They are doing the best they can.

Moving back to Vonage is probably your best bet. I don’t know if you’ve heard, but T-Mobile just discontinued LineLink, like, as of yesterday. They’re not letting anyone else subscribe to it, and they’re using their leftover adapters for warranty/parts for current LineLink customers (until those parts run out...)


They were just talking about this on a couple other websites:

Tmobile does not work with vonage and tech support says they don’t support voip at this time but they are working on it. I am going to leave tmobile internet until they fix it

Tmobile does not work with vonage and tech support says they don’t support voip at this time but they are working on it. I am going to leave tmobile internet until they fix it


I’m not sure what you’re saying… The OP would just need to port their LineLink number out to Vonage. They’ll have to use a Vonage adapter…. not the LineLink one.


I’ve had T-Mobile since 2000, and Vonage for my landline since 2003. They’re two separate things, and everything works just fine. One doesn’t even know the other exists.

I am talking about the new Tmobile home internet service/device.  Does not support VOIP.  I dont know about the older white boxes.   Sales says they do support, tech service and actual testing says VOIP does not work.   There are no controls to the gateway that we have access to.  There is no DMZ to put your VOIP device in etc.  Zero admin controls on the new internet device they are shipping.   I have Vonage and it did not work with the new grey tower gateway tmobile provides.   Would love to have a solution so I dont have to cancel. 

Ah, you were talking about T-Mobile Home Internet. Thank you for clarifying.

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My guess is LineLink uses IPV4 and T-Mobile uses IPV6 only.  When using other devices there is built in tunneling sometimes and why it works.  

Ok. So here is a workaround.  I was also told by a tier 2 tech that they had fixed the issue with VOIP and that it would be out in the next firmware update, which he said would have been delivered 2 months ago.  So stop waiting for that.

I changed my provider from TMO Line Link to 1-VOIP.  They have a plan that if you prepay for the year works out to about 152.00 for the year, including the shipping of the device.  When I first received the device it did not work with the TMO Nokia device, as expected.  I was using it with my old ISP instead, until they finally caught up with me that I had cancelled service with them.  So today I spoke with the tech at 1-VOIP who said that they had indeed created a change on their side so that their service would work with the TMO Nokia device.  It had to do with changing the port, I believe.   In a matter of minutes I was up and running.  Let me know if you need help with 1-VOIP.  I don’t get anything for a referral so don’t think I am pushing them.  But their customer service is in the USA and I appreciate them taking the initiative to work out the problem for their customers that have the TMO Nokia device.  So I want to reward them by recommending them.  You WILL NEED TO CALL TECH SUPPORT and tell them that you need the fix for use with TMO Home Internet with the Nokia device.  It will NOT work out of the box.