At Jakarta, Indonesia...

Connects directly onto Telkomsel Internet and voice quality on local calls is pretty bad.
Very difficult to pick Indosat even manually, and when connected no internet

So far this is the worst connection I have had...

That's hardly T-Mobile's fault...sounds like a bad local carrier or bad coverage area.

Flyertalk to the rescue! (I think)
 

Flyertalk to the rescue! (I think)

Arrived in JNB airport late afternoon/early evening, powered up to iPhones (6s and 6s Plus). Network search for a good 10-15 mins and finally picked up on one of the networks (honestly can't recall which one). Once they grabbed a network - full signal bars ... nothing. No data access, web sites wouldn't load, apps said in substance "no network connection," iMessages would not go through (offered option to send as Text Message). However, I COULD make calls (back to USA and intra-South Africa).

Called T-Mo customer care and spoke with folks in Texas call centre. Helpful and they tried (reset network connections, toggle cellular data on-off, power off/on, etc) but nothing. They put in an escalation ticket and promised a call back within hours to see if anything was working and that ticket would be resolved within 72 hours.

Used an AT&T iPhone that was working to ask the Google for a solution. Saw a lot of sites discussing SIM-unlocked phones having issues with the insertion of new SIM post-SIM unlock. That's not me. Phones are new/fresh from T-Mo with T-Mo SIMs that had never been removed.

Flyertalk thread came up (perhaps this one, I was doing a lot of this on-the-fly while juggling about 6 other travel-related issues) and saw note about "reseting" phone by turning off while holding the home button. Also saw note to enter #RON# and/or #ROF# into phone dialer. Did that on both, toggling data off then back on with confirmation messages back from the phone.

That seemed to "do it" Data immediately began flowing, emails, incoming iMessages, outgoing/outbox messages dumped out and were now sent, etc.

I suspect that the #RON# #ROF# toggling took care of it rather than some magical action by T-Mo escalations. Indeed, the lack of a phone call or message back from T-Mo customer care indicates the ticket is still unresolved (i.e. they haven't "fixed" my problem).

Of concern was almost immediately ALSO started getting SMSs from T-Mo saying you've used $xx amount of international data roaming. I thought that I had perhaps toggled on the higher-cost "full-speed" data plan rather than just the slower "free" international roaming. Called T-Mo customer care back and spoke with fellow who told me that I was cool and that these messages were sometime sent in error but that I was good and on free data. He noted my account so that, if I get nailed with a huge international bill. Hold thumbs.

So your call to the US T-Mo Customer Care worked on those networks but the data didn't?

That's odd.

Did you dial 611 while roaming on the international networks to reach T-Mo customer care?

More often than not the hard reset solution usually solves the problem. Glad your all set!

i actually had the opposite problem while in mexico where data worked and voice didnt, was only there for a few days and they said it would take 48 hours to fix...

Hi,

Has anyone tethered their laptop or iPad to their iPhone, Galaxy, etc cellphone while using the free internet roaming? Did it work well? Did you get charged anything extra?

While it is not a direct answer to your question - the fine print at the bottom of this page says "no tethering":

http://www.t-mobile.com/optional-services/roaming.html

Pretty sure I've tethered my phones to my iPad, which had the SIM.

Again, not fast but worked.

Tethering does NOT WORK while roaming IME Thailand, Malaysia, etc. Even thought sometimes you can turn it on on the phone, it doesn't work.

Tmo has some plans with the ability to roam (simple choice) if using a tablet with a sim, BUT if you don't have a plan that allows it I was told a few days ago that IT TAKES 5 WEEKS for it to go into effect, so my thought of adding a higher level to my sim tablet (and taking it instead of my preferred one with only wifi) for a trip next week is a no go.

So much for no contract instant change of service!

Macau -- Phone roams onto 3 Macau, data not working. Text and voice works but data doesn't ("PDP authentication failed" as reported earlier in this thread). Tried all the steps listed in earlier posts in this thread, reboots, #ROF#/ON, LTE on/off etc. Other networks when manually selected only get "no service".

iPhone 6s and 6s Plus. Worked in Taipei as expected just 2 hours earlier.

Called TMO, they claim 3 is the only network that would work at all, and that data service would NOT work. The other two networks are apparently still being built out. That is what TMO support actually told me.

Connected Directly to TMO in Houston, LTE, Unlimited Talk, Data, Messages... WOW I missed this so much!!!

;)

Used in Grand Cayman and Bahamas (specifically, Disney's Castaway Cay) last week. It took a couple of cycles of airplane mode on and off, but I finally got the welcome text messages. Grand Cayman was Digicel; Bahamas, BTC.

As always, great for checking e-mails, sending text messages, chatting on Hangouts, and posting the occasional Facebook picture.

Had an odd bug a few days ago in South Africa. Despite being on the plan, I got 2 scary texts. One was that I had hit $100 in data and one that I had hit $200 in data. Called customer care and they said there were no charges on my account and were going to write up the scary bug.

In addition to Bell and Rogers, Telus most certainly has LTE roaming in Canada. My phone seems to default to Telus, then goes to Bell. Have to force Rogers, but I don't really care.

I find the same situation in Canada. However, I have had it default to Rogers, either because it couldn't connect to any other networks, or because Rogers was much stronger.