Reddit reviews SIP: Understanding the Session Initiation Protocol (Artech House Telecommunications)
We found 2 Reddit comments about SIP: Understanding the Session Initiation Protocol (Artech House Telecommunications). Here are the top ones, ranked by their Reddit score.
This book really drills into level SIP and makes it a little more easier to understand the RFCs - https://www.amazon.co.uk/SIP-Understanding-Initiation-Protocol-Telecommunications/dp/1607839954
Its rather expensive, but you might be able to find a copy.
Also, install FreePBX, an Asterisk based PBX on a VM / Raspberry Pi / Old PC and start playing around with it.
Best book on the SIP protocol
https://www.amazon.com/SIP-Understanding-Initiation-Protocol-Telecommunications/dp/1607839954
Best book on SIP Trunking
https://www.amazon.com/gp/aw/d/B003ATPQEI/ref=dbs_a_w_dp_b003atpqei