Jailbreak is a tiny but complicated process and for the first time, it might seem lucrative but it isn’t. Jailbreaking involves risk. Risk of data theft, malware or adwares, risk of making unstable performance, and lot more and that’s not yet completed. In past, with iOS 5 and earlier iOS version, People used to install a hack that involved SIM Spoofing, to obtain network access even on carrier-locked iPhone. Since you know what locked iPhone means, Jailbreaking is most desired solution to get’em unlocked free. But wait, Apple engineers have improved iOS security and thus, jailbreaking process became a lot hectic and sometime it is not just possible to jailbreak. Since 2012, Jailbreaking is not able to heck network access related parts and thus, jailbreaking is now limited to install patched games, apps and themes. Yes! No more unlocking is possible with Jailbreak. Even though if you are using old time unlocked iPhone, you can not upgrade to latest version. Each time you want to upgrade iOS firmware, It requires a lot things. First thing you will require is if jailbreaking for that Model + firmware is available or not. Along with availability of jailbreak options, There has to be a solution to run any SIM card on carrier-locked iPhone. However, That part is not possible any more and thus, Jailbreak is not network unlock.