He didn't answer my call (?)?

I had my first telephone conversation with a guy whom I am interested in over the phone. we'd been texting back and forth all day because he was at work. Our conversation began on his drive home and continued some after that. I had to go though and asked if I could call him a little after I had finished around 8ish central time. He agreed, saying he wouldn't be drifting off to sleep until around 9:45; but when i called him, he didn't answer. it's only 8 o'clock. it's been 45 minutes and still nothing. well, i wouldn't be that picky if he had called me when he said he would, either after the superbowl or yesterday and I didn't get a call on either times. I text him this morning to see if he was still interested in a conversation and this is what kicked started everything. don't forget we texted all day and talked on the phone for about an hour. I am a bit older. He is 35 and I am middle forties. he says he has never dated anyone older, but they'd always been 5 to 8 years younger. is he interested or not?