Hi, just to confirm "something", Im having this issue, my wife is, my mother in law is, my work colleague is AND my macbook is. Its not iphone specific, its not ipad specific and its not macbook specific...
Have just spent an hour chatting with support about it - we've done hardward recycles, network router reboots, etc, etc and i will get a call back tomorrow with some more suggestions.
But as I have pointed out - all 5 devices are on different networks, different OS versions (5 thru to 7) and in different locales around UK.
Theres not one common element to indicate an issue with OS5, or O2 network or BT broadband - we're all different yet are all having the same issue.
On the basis of A and B testing Ive been able to show Apple Support the only constant in this is Facetime - thats the only thing linking us all together as a common point of failure.
Currently their opinion is all facetime servers are green lit without issue having gone to view the status.
I have directed their attention to the forum threads in the last 24 hours here that all relate to facetime - therefore the old "have you tried turning it on and off" is redundant - its definately not an individual phones fault - its service related.
Id be confident to say issue lies at the facetime servers in some capacity.
I hope the last hour of my time with their advanced support staff has been able to show and eliminate any issues from the consumers side so we dont have to go through the basics and instead we can get some techs looking on the service and server side.