SIP main functions

1. User location - locate the end user geographically
2. User availability - available, busy, DND presence infomation
3. User capability - determine the media being used and parameters associated with the media
4. Session setup - establish session parameters for both caller and callee
5. Session management - transfer a call, end a call, or modify session paramaters

https://tools.ietf.org/html/rfc3261

读书笔记 - Atomic Habits

读书笔记 - Elon Musk (part 2)

 Placeholder to mark my reading progress. Will add note shortly.