I just got my x101p off the ground on fedora and i thought I might mention a few tips for those getting started:
X101p hates being on the same PCI bus as any other card, so you might have to do some shuffling. check /var/log/messages for details. “fxo abort” errors mean the card is conflicting.
Zaptel drivers for fedora are…erm…difficult. for simplicity, remove all prior copies of kernel-devel using yum, then install the latest kernel for your core (3,4,5,etc) and install its accompanying kernel-devel (Fedora calls kernel source the -devel package.)
Reboot into your new kernel with its sources and try to compile zaptel kernel module, although for me it failed to work in core 4 for some reason (compilation success with make and install, but no module found!). Dont panic, many people have generously contributed Fedora Zaptel RPM’s and a google search should find them easily for your platform and version.