I think when I looked at it it was pretty basic, I'd personally probably favour the opensips bootcamp over that. You learn opensips but also learn about SIP at the same time. https://opensips.org/training/OpenSIPS_eBootcamp_2022/
When I first started to look at SIP many years ago, and I inquired about documentation or a manual, I was told "RFC3261 is your guide" and I believe that is largely still true today: https://www.rfc-editor.org/rfc/rfc3261
Thanks for asking this question. I came across the sip school and was curious about it as well. Thanks for the responses. I'm going to check the RFC and book out.
Hi All,
Thanks for the feedback this is appreciated and I have placed an order for the book. The opensips bootcamp looks great but timing and cost are factors working against me!!
Doing further digging I think https://www.voip.school/ also looks decent but maybe a bit basic but getting stuck into something while getting Fusion setup has got to be useful.