This is what I do whenever I am deployed...I have an AAFES phone card, which I buy in the PX, not really sure where civilians can buy them, but they are sponsored by AT&T, and I dial back DSN to a base operator. I then get the base operator/staff duty to dial the toll free 1-866 number, and use the phone card as if I was back in the States..I use the minutes as if I were back home. Hope that helps you some.
I was wondering if that would work. I'm not sure if he has easy access to a DSN line, but that could be a backup option. Thanks.