all pdn ip connection failure

So when it comes to IPv6 adoption it is taking place. The US is in the top 4 countries using IPv6. The innovative companies tend to adopt IPv6. It is used around the world in many locations but has a long way to go to be the dominant IP stack. As long as software vendors rely upon IPv4 it will hold things back. IPv4 is the past. IPv6 is the future to improve communications and cellular vendors know this. T-Mobile has a huge number of IPv6 and IPv4 addresses. For now both exist and NAT is only required for IPv4 legacy models. India, China, & the US are the top three countries using IPv6. It is out there.

Popular sites using IPv6

• Google.com
• Facebook.com
• Microsoft.com
• Youtube.com
• Netflix.com
• Instagram.com
• Apple.com
• Live.com
• Linkedin.com
• Wikipedia.org

I think it is important to keep in mind that T-Mobile is a mobile carrier first and foremost. It is common for cellular carriers to use IPv6 due to the sheer volume of required IP addresses. Sure the IPv4 to IPv6 translation does impose some limitations but seriously if software vendors would embrace IPv6 the performance for communications would probably improve and the limitations imposed by IPv4 and port forwarding that requires NAT could be remediated. IPv4 was adopted for use in 1980. Seriously the problem is more with software vendors that use the old IPv4 protocol stack and do not leverage IPv6 technology. 

I will not try to defend T-Mobile and their practice of over subscription in some market spaces. If the towers and backhaul paths are over subscribed and excessive traffic prioritization is required well that is indeed an infrastructure issue that needs improvement and well that takes more money and engineering. My experience here with the T-Mobile solution has been very positive most of the time since January of 2021. When work was done to upgrade from n71 to n41 it was indeed a week of disruption. Over all most of the time it works. It really depends upon the local environment. We are in a rural location not dense urban so the saturation is not bad. Will that change? Time will tell as the area grows that could well be the case if they do not have proper planning. So far it has been really good. Is it perfect? No but it hands down beats the life out of the DSL solution we had in CA for reliability and consistency.

There are lots of variables in the cellular signal delivery so the problems there may be a combination of factors and NOT just a IPv4/IPv6/IPv4 translation complication. The fact that there are three different gateways and odd issues with each does not help. OK so four if you include the LTE gateways that are still in service. The software and/or hardware issues with the gateways are just as likely to be a factor. Each edge access gateway solution has its unique challenges so I just don't tend to believe there is any single reason. I find it helpful once every 45-60 days to just reboot the gateway to flush it out. That isn't always necessary but it seems to clear out odd behavior. Sometimes it might seem like a network issue only to be a problem with the local client. My iPad Pro is notorious for needing a reboot whereas my MacBook Pro or my Linux clients tend to have few issues. The Windows client still here well it usually chokes on Microsoft updates and it is a Alienware gaming rig with plenty of resources. I see Linux looming on the near future for that client. There are just too many variables to blame the CGNAT alone. There is nothing else for us here that can touch the cost and/or performance of the T-Mobile internet solution. We just are in a great location to get good cellular internet communication.

T-Mobile is 100% overselling yet again. The issues with ip versions are because ignorant TMO continues to have a crap CGNAT system that does not properly translate ipv6 to v4 and vice versa. 99% of the time I have to turn off and back on until it properly connects me to a tunnel for ipv6 to v4. It has been over 2 years now that ive had TMO and this issue the entire time Ive been with them. They don't care and are never going to care because they can't get it right and are more worried about grabbing customers from other companies than actually providing a NAT service that works. I'm honestly surprised that no lawsuit has ever happened because of this. My guess is because the Business customers on T-Mobile DO NOT have CGNAT and are givin real public ipv4 addresses instead of this crap with ipv6 to v4 translation. The majority of the world still does not have ipv6 tables setup.

Depending upon the gateway you are using that might have something to do with the change. If you have the LTE WI-FI Gateway you should inquire about upgrading to the 5G solution or at least give it a test drive and consider it. If you have an iPhone put it into Field Test Mode dial, *3001#12345#* ,enter and look at the cellular information. If you have a phone that only supports LTE that might explain the behavior. T-Mobile may have upgraded equipment on that tower and now the equation has changed. If you get the PCI information from the gateway for the cells then you can use cellmapper.net and look for the origination of the cell sources. If tower changes have been made then maybe a relocation of the GW in your home might help but not if T-Mobile is currently making changes and/or improvements on the equipment.

• Network Bands T-Mobile Operates 
  • Bandas 5G: N41, N71
  • Bandas 4G LTE: B2, B4, B5, B12, B71, B66

Sprint & Boost Mobile owned B25/B26 and T-Mobile uses the ABOVE 4G LTE bands with the home internet GWs. So what sort of gateway are you using? 

 Gateway Nokia 5G21, Gateway Wi-Fi LTE T-Mobile, o Arcadyan KVD21

I wish TMobile had real support for this type of issue.

I am getting more answers on Reddit than I am from any help desk or Tforce on Twitter.

At this point, I think early adopters of TMobile internet are getting throttled because the product is oversold and it is causing slow downs for new customers. They want new customers to stick around. My internet is consistently down Sunday - Tuesday. Then Wed - Saturday, it miraculously works.

No one at TMobile can help and if it blips again (been happening since May 15th) Sunday, I’m giving up. 

Just speculating a little more given the relationship between the SIM card and the behavior. The PDN connection is probably related to the external IP not internal IP addresses. That is where they would enforce security and controls when the node joins the network. The SIM and the ICCID provide the device/user identification for verification. The ICCID is specific to the SIM. The IMSI number is specific to the user so the combination of the two connect the device with the SIM to the user. If any of that does not add up no PDN connection will not be formed.

Sorry, just thinking it through. If the support database had a proper search engine and included data related to the error codes then the front end support people could probably go to a second level engineer and provide answers that clarify problems so users don't feel like no one knows squat. Providing info as such might be way over the top for most users but if it is relayed at a level that makes sense to the common user then it could help. I myself like to have answers to odd issues. Sort of like on the WIFI statistics why does the gateway always report "Sent Errors" on the WIFI networks? What does "sent errors" really tell anyone if no one can translate what these are? 

I know it sounds like Greek but well… "The PDN connection is a logical connection between a specific IPv4 address and/or IPv6 prefix allocated to a UE and a particular PDN. This is the user IP connection. This is a common feature in mobile networks where the user plane is tunneled over a transport network in order to provide per-user security, mobility, charging, QoS, etc." Science Direct

https://www.sciencedirect.com/topics/computer-science/network-connection

My guess is the programming of the equipment for the radios is in need of attention. Something fundamental is amiss for the user's IP connections. I found the information and just took what is more specific to the conversation. You asked.

5 calls later I got a rep that seemed to know what the PDN error was.  He had me remove the SIM card and then he changed the frequency of my gateway to better talk to the tower after it booted back up. So far it's back to normal with no errors. 

New sim card and two trash cans later same issues persist with me finally being sent the black device I hope this one is better than the trash can it's the only good internet in my area and my ol lady relies on the internet for her work from home job to TMobile y'all need to figure out what the PDN IP codes are and y'all need to figure out what "modem chip down" is I'm so sick of these two critical and major alerts that prevent my wifi from working I understand service is only 55$ but I'm also not gonna pay for service I'm not receiving yet again 

Same issue, been happening since May 15... It's now May 25.

I've called T-Mobile so much I'm tired. I'm pretty much going to give up at this point and get another service