As I’ve been saying for years, your comment is not only true about pjsip - it is true about the entire project as a whole. People will point you to the wiki, but if you take a look at the wiki, you’ll find that it is a jumbled, disorganized mess. For some parts, there’s nothing. For others, the information is grossly outdated.
If you check the links in the Module Admin module for FreePBX, you’ll find many of the links to the Wiki are broken.
The Wiki entry for the Trunks Module is an example of a disorganized mess. The section on pjsip is clearly an afterthought, with useful nuggets like “Retry Interval - How long between retries,” but no explanation as to WHAT is being retried (most likely it is registration).
https://wiki.freepbx.org/display/FPG/Trunks+Module+-+User+Guide
There are some nuggets in the Wiki, but there are a lot of pages that contain no useful information whatsoever, or are filled with jargon.
The tooltips in FreePBX are also hit or miss. Some are quite useful. But, some are really nothing more than taking the field title and rewriting it in a sentence. In other words, if the title of the field is “Field Title” the tooltip might be “Sets the (Field Title”). Uh, thanks.
Early in the project, there was even less documentation than there is today. Since the product is free, a lot of people wrote extensive, step-by-step how-tos. Two of the greatest writers were WiseOldOwl and MichiganTelephone, but both of them eventually just gave up because the rest of the community were so hostile to them that they couldn’t stand it anymore. MichiganTelephone had a great blog that you could follow step-by-step to set of an amazing open-source FreePBX without having to ask anyone a single question, but he deleted the whole thing in disgust. Here’s what’s left:
I took up the torch for a while and wrote a lot of stuff for the Wiki. Tony Lewis even offered me the job as Community Manager, but I turned it down because my day job is better. He hired someone else who came in an butchered much of what I wrote. You can see his influence in the Trunks documentation that I linked to above.
For comparison, you can see the Trunks documentation that I wrote here:
https://wiki.freepbx.org/pages/viewpage.action?pageId=20152464
(Note that GUI changes made to FreePBX by the devs made the screenshots that Included obsolete.)
And here’s the article I wrote about linking two FreePBX systems together, which the new CM left intact for some reason:
https://wiki.freepbx.org/pages/viewpage.action?pageId=4161588