Sangoma does/did not release a source RPM but were kind enough to give me their
spec file when I asked for it. Unfortunately it did not use a build root and
expected to find a lot of files pre-existing on the build host.

I had to extensively hack the spec file and the Setup program to get an RPM 
to build. I have sent these changes to Sangoma and hopefully they will use 
at least part of my changes to re-release their RPM.