Connect my phone to the network to make calls

When abroad, your phone should just connect automatically to a local network when you arrive so you shouldn't have any problems making calls right away - also make sure you are in a country that supports Smarty EU roaming (or that you have an 'out of plan' add-on for countries outside the EU). With data you just need to check the APN is set to 'mob.asm.net' - incase you're trying to make a call using data.