As I recall, Alexis first tried dialing his number, which didn't go through, and then switched to using Skype, which I gather is some sort of online videophone service. Maybe with Skype you don't need an international code.
(Ohh, look at us... two professional science-fiction authors struggling to keep up with present-day technology.
It's not just us. John Ordover and I were debating this very issue just last night.