Recently had a business trip to a remote location in Laos. I got dtac data roaming before I went but once I crossed the Ubon/Laos border I found that dtac data roaming was a waste of time as the laos phone service I connected to was poor or intermittent. Money wasted.

While I was at the laos office though, I connected to and used their wifi for internet. I also think I was able to call home using Line call or WhatsUp call (would that be correct? ).

I may have to go to a remote location in Vietnam for business and was wondering whether to forgo data roaming and use wifi/Line/WhatsUp.

Any advice?

DTAC (and AIS, and TrrueMove H) all support Voice over WiFi,, so that may be an option for you. This is the exact application it is meant for.

 

https://www.dtac.co.th/network/wifi-calling.html

 

If you have data (WiFi included) any app which supports messaging, voice and video would work assuming "home" or whomever you want to "call" is running the same app.

 

 

 

^Thanks for that tip. I couldn't find it in english but I found this link (for anyone who reads this later)
http://en.postupnews.com/2016/03/dtac-wifi-calling-vowifi.html?m=1

Sorry about that, it just auto-translated for me, didn't even realize it wasn't in English.

 

 

https://truemoveh.truecorp.co.th/news/detail/198?ln=en

 

http://www.ais.co.th/4g/vowifi/  (in Thai only)

 

There have been quite a few threads here on this feature.

 

Before you use your Thai SIM card in another country, check the rates. You may find them outrageously expensive. I tried it once in the US and although it worked well, my balance was used up VERY quickly. I ended up buying an AT&T SIM.