TIPS T-mobile Blocking SIP?

Thanks, @atsak and @wardmundy. Were it just for me, those options might be fine. But they are probably out-of-scope for what I'm trying to do here.

(1) True, the KVD21 doesn't have configurable ALG control. Doesn't have much of any control, even using the Hint Control app. But I don't know if that actually =is= the problem. Haven't ever read an "ALG is for sure the issue" confirmation -- happy to be pointed to that fact -- and @wardmundy said he used IAX and VoIP.MS without issue, suggesting it might be a SIP port blocking problem. I don't want to have to be buying new hardware to suss that out. I'll pop the C4P SIM into my iPhone and then my Moto G Power and either tether or hotspot each to the desktop to see if that gets around the problem.

(2) I'd be all over the GL-iNet router for me, but that's out-of-scope, price-wise, for the intended application. $500/year is a bit over the less than the $215 first year, $180/year thereafter price-point that the used KVD21 and C4P would cost the low income families that I'm intending this for. If it just doesn't work with VoIP, and there is no work around, it'd be cheaper for them to use something else for home telephoning.
Can't beat this pricing for home phone

 
@tycho: I think the Calyx folks have a much cheaper low-income offer for those that qualify. Not sure if they provide it or their supplier does. But it works exactly like the Calyx SIM card because their provider fulfills the offers. The company is Mobile Citizen, and it's about $120 to $160/year. More info here. You can contact them here and explain your use case. It looks like one of their low-income suppliers is here. Must meet their Gold Membership qualifications for $160/year pricing. Another Calyx lowincome supplier is PCs for People. See Bridging the Gap offering.
 
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@tycho: I think the Calyx folks have a much cheaper low-income offer for those that qualify. Not sure if they provide it or their supplier does. But it works exactly like the Calyx SIM card because their provider fulfills the offers. The company is Mobile Citizen, and it's about $120 to $160/year. More info here. You can contact them here and explain your use case. It looks like one of their low-income suppliers is here. Must meet their Gold Membership qualifications for $160/year pricing. Another Calyx lowincome supplier is PCs for People. See Bridging the Gap offering.
Thank you! I think Computers 4 People is also using Mobile Citizen (would have to check) but was under the impression that Caylyx was much more expensive. Will investigate.

I am merely trialing options to provide to folks coming out of an abuse shelter that I support. C4P was super easy in terms of getting the SIM; it is less than $15/mo., and for any basic home Internet use case it seems to work fine. I'm the one who threw the monkey wrench in the works by trying to see if it supports inexpensive VoIP providers because I was trying to create an inexpensive bundle of Internet, home phone (with new number for perhaps obvious reasons) and CPE (cheap gateway and soft phone). The inability to handle SIP calls was unexpected. Didn't do my research -- I now realize SIP failure is a hot topic with T-Mobile Home Internet. That's why I made my post; looking to see if there is a work-around or if I should just delete that functionality and stick with working only the Internet angle.
 
@tycho Looking at various posts about the T-Mobile home internet, I see that they block UDP on ports 5060 and 5061. A lot of people have been able to fix the issue by moving to a different port number and using TCP instead of UDP. I don't know if you tried that or not. There doesn't seem to be consistency with the issue as the various T-Mobile routers handle it differently.
 
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@tycho Looking at various posts about the T-Mobile home internet, I see that they block UDP on ports 5060 and 5061. A lot of people have been able to fix the issue by moving to a different port number and using TCP instead of UDP. I don't know if you tried that or not. There doesn't seem to be consistency with the issue as the various T-Mobile routers handle it differently.
That's what I had read -- that T-Mobile home internet blocks UDP on ports 5060 and 5061. I will see if the VoIP providers that some of these folks are already using can accept TCP traffic over non-standard ports. And no, haven't yet tried that but intend to; perhaps even tonight.

I =had= thought that using something like Tailscale would be a work-around, but maybe not if the traffic is still destined to 5060/5061. I've been able to use Tailscale perfectly fine when connecting an extension to my Racknerd PBX using the Computers 4 People TMo SIM. I can access my conference channel perfectly and chat with others. But I can't make an outbound call via several different VoIP provider trunks -- nothing but 408 errors. So, time to do some tinkering.
 
Not sure what the secret sauce is to your comment above, @billsimon , that you are able to "use SIP over T-Mobile Home Internet daily." I have VoIP.MS, and read a comment by @wardmundy that he was able to use T Mobile Home via IAX, and will test that. But the folks I am concerned with already have put money in accounts with VoIP providers that do not support IAX and I'd like them to not waste that money.
The PBX was in cloud and the endpoints (behind the T-Mobile internet) were connecting to it over TLS. This worked fine. Unfortunately I can't offer any testing right now because I'm using a different ISP as primary, but the T-Mo remains around as a backup. I've still got the gray cylinder modem, and that may make a difference, because I know T-Mobile is sending out different modems now.
 
The PBX was in cloud and the endpoints (behind the T-Mobile internet) were connecting to it over TLS. This worked fine. Unfortunately I can't offer any testing right now because I'm using a different ISP as primary, but the T-Mo remains around as a backup. I've still got the gray cylinder modem, and that may make a difference, because I know T-Mobile is sending out different modems now.
Thanks for the tips. I've been testing with a cloud instance of IPBX on racknerd and numerous softphones, plus connections direct to several VoIP vendors. I will try focusing on TLS. I have access to a KVD21 and and LTE-only Netgear LM1200. Maybe some combination of ingredients can make for an inexpensive home Internet and home phone package that, assuming one can acquire the cheap modems from ebay, might work.

An inexpensive used T-Mobile cellular router plus the various low-income Sims that have been discussed in this thread in my opinion work just fine for basic mainstream home internet. I am the one who made things more complicated because I had started this project long ago simply directing folks to inexpensive VoIP for their home phone needs. I was hoping to figure out a recommended package so that both voip and internet could be combined, but that has been my downfall. Might need to go back to treating them separately, at least where T-Mobile ends up being the home internet provider.
 
An inexpensive used T-Mobile cellular router plus the various low-income Sims that have been discussed in this thread in my opinion work just fine for basic mainstream home internet. I am the one who made things more complicated because I had started this project long ago simply directing folks to inexpensive VoIP for their home phone needs. I was hoping to figure out a recommended package so that both voip and internet could be combined, but that has been my downfall. Might need to go back to treating them separately, at least where T-Mobile ends up being the home internet provider.
I think it's only the T-Mobile branded home internet service that causes this problem. We've never seen it with Calyx which also uses the T-Mobile network.
 
I think it's only the T-Mobile branded home internet service that causes this problem. We've never seen it with Calyx which also uses the T-Mobile network.
I've not experienced the problem myself with T-Mobile =cellular= service for cell phones, used in a cellular router, but I do seem to be experiencing it with this Computers 4 People SIM. It is being used in a T-Mobile-branded modem/gateway/combo (the KVD21), and the auto-provisioned APN (which I can not change on the device because it doesn't want me to hurt myself, *heh*) is FBB.HOME. I know that is the APN used for TMHI.

Not sure what would be different about Calyx, other than perhaps it is a data-only, tablet-style cell product whereas the C4P does indeed seem to be repackaged TMHI. What APN do you know is used by Calyx?

C4P is getting their underlying T-Mobile service from Mission Telecom (see https://www.telecompetitor.com/miss...-4-people-partner-on-low-cost-hotspot-access/). Google AI tells me that Mission Telecom is one of the "master agents" (alongside Mobile Beacon and Mobile Citizen) that administers special non-profit plans. These plans originated from legacy Sprint/Clearwire spectrum agreements that T-Mobile assumed after its merger with Sprint. Google AI also tells me that Calyx service instead "is administered through master agents Mobile Beacon and Mobile Citizen."

Not sure why there should be any difference at all in what is provided by Mobile Beacon/Mobile Citizen to Calyx vs what is provided by Mission Telecom to Computers 4 People, but there might be something.

I think I might try my LTE-only Netgear LM1200 to see if it changes things. At least with that device I can change the APN (I would try fast.tmobile.com or perhaps B2B.tmobile.com).

Thanks for the assist...
 
Not sure what would be different about Calyx, other than perhaps it is a data-only, tablet-style cell product whereas the C4P does indeed seem to be repackaged TMHI. What APN do you know is used by Calyx?
Our Calyx account APN is fast.tmobile.com, and we're using our own GL-iNet GL-XE3000 router.
 
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