Every few years I make an attempt to get into SIP/voip, but so far my experience has always been the same: Wall-of-text like documentation that makes no sense, huge cryptic config files, tutorials that assume you already know everything or that just don't work, software that only works with such-and-such kernel, conflicting information scattered across the globe. It feels like trying to set up Slackware in the early 90s. After a few hours I get tired and drop it again.