Can Telstra Unlock My iPhone that is Locked to AT&T and Lock it to Telstra?

Hi if you unlock your mobile then it can be used any where and it is not necessary to unlock every time you use different network..Hi,for iphone there is no unlock codes but instead we can do it by remote unlocking..there are many online providers who provide the service..one of my friend got unlocked his iphone from onlinegsmunlock by remote unlock..and the important thing remote unlocking is avaliable for some country and network providers only so if you are interested you can try from them before that see whether remote unlocking is available for your country and provider..