Does jailbreaking your iPhone allow it to be used on any network? Does it unlock it?

I want to jailbreak my phone so It won't be locked on EE and I can use my talk talk mobile sim.
I don't want to unlock it at EE as you have to have been with them for 6 months and I don't want to have to wait.
Will jailbreaking it allow it to be used on any network?

Read this link, it says you can unlock but when you link to itunes it will re-lock to original network.