If a person went to rest with SIM card registered in the home region (in other words, lives in Irkutsk and Irkutsk went with a SIM card), call him with a mobile phone is not difficult: you pay for you will be implemented according to current tariff plan.
Net calls on many tariffs free. But the camper people would be considered as roaming, that is, the payment will be made for incoming and outgoing calls.
To call abroad from a mobile phone in the case when people have left for permanent residence and registered a local number, you must comply with the rules of international dialing.
When you call to a landline number you need to dial: 810 - country code - city code - subscriber's number or +country code - city code - subscriber's number. When you call on a mobile phone: 810 - country code - operator code - subscriber's number or +country code - operator code - subscriber's number.
Note: for a call to Ukraine using Ukraine code 380, but all local numbers begin with 0, and gain a +380_0... there is confusion, and the system responded: "Wrong number". In order to avoid errors it is recommended to dial +38 (instead of 380), and further the number from 0.
It is worth noting that to call abroad from a mobile phone does not always work in connection with expensive rate: calls charged from 6 roubles and above (depending on call direction and tariff plan rates). Save the situation can Internet applications like Skype, Viber, WhatsApp etc. At a relatively inexpensive Wi-fi calling app goes even more profitable.
On the old tariff plans to call abroad using VoIP call over IP (also via the Internet, but without using any extra apps). For this mobile phone, you must dial: 147 - 810 - country code - subscriber's number or 147 – 810 – country code – city code – subscriber's number.
The new tariff plans (for example, tariffs Tele2 "Black", "Very black," "The black", "Orange", etc.) service of IP-telephony is not available.