I just recently switched over to pjsip and I have to say that despite being legacy, chan_sip has a lot to recommend it.
Prior to the “upgrade” all of my extensions “just worked”. Now I have extensions which randomly turn on DND on their own, or lose their registration randomly ( despite showing as registered ) ( same subnet, same physical network, so no firewall between endpoint and server ). I’ve had a few core dumps as well, whereas I never experienced that with chan_sip. Compounding these issues is that I have yet to find anything online related to these issues, despite extensive looking.
This may very well be related to all the modules that are being loaded; chan_sip has one module to load, whereas PJSIP has 30+ modules to load, not all of which are clear on their purpose. There doesn’t appear to be any documentation related to which module does what, either ( at least not that I could find ).
I can accept that all the issues I experienced were related to my own ignorance ( I assume this is the case as I’m sure others are using PJSIP in their own environments successfully ), and would love to correct that ignorance; but I don’t know where to look for the relevant data.
And like I said; chan_sip just works.