You're right about Pole but McMurdo is also satellite also. You might be thinking of how it gets back to the US? There is undersea fiber from Australia back to the US, but it's a satellite hop from here to Australia.
I could have sworn the tech guys said it was a direct connection, which is why the speed was half decent and there was no down time. That was in December 2012, maybe things have changed since then? I could be wrong though, I didn't spend a lot of time in McMurdo, just a few days while we prepared to head to the pole and one day on the way back.
It's certainly an interesting place.
I'm in IT so I've had a chance to talk to all the appropriate people about the setup. Its satellite for sure, just ask our satellite engineer.

Our satellite is just above the horizon all the time so we get the 24/7 coverage, which is different from the Pole. We have a microwave connection from McMurdo across the sea over to Black Island(about 20 miles from here), that is where the signal hops on the satellite uplink. Then down to Belrose, on to the undersea fiber to LA, then through the public networks over to Denver where HQ is. That's where the phones and internet come out, so that's why phone calls and internet from here appear like they're coming from Denver.
It's still the same now and probably will be forever. As much as a direct connect would be nice there is too much glacier activity. When huge chunks of ice go floating out to the sea some of them scrap the sea floor, that would wreck havoc on fiber lines in the area.
You've got one up on me though because I've still never been to the Pole.