Ipad facetimes Iphone successfully but Iphone calling Ipad says busy immediately

I have the same issue except mine is with the iMac. No problem facetiming from the iMac to the iPhone 4S but not from the iPhone to the iMac it says that the iMac is busy. This is also on the same wireless network and the network is fine as the iMac does not lose connection. I am going out shortly so I will test from a different wi-fi network. Apple please please acknowledge and reslove...........

margaretfrommarion wrote:

I can call my iphone from my ipad using the phone #. When I call ipad from iphone using email address, I get an immediate message "is busy at this time"

Any ideas?

I have finally resolved this (without help from Apple).

I presume you are using the same Apple ID for both the iPhone and iPad. If so it is the email address which is conflicting. Remove the email address from the Facetime settings on your phone but leave it on the iPad. You will be good to go.

If that doesn't work let me know.

Thanks that solved my problem too!