This week's lecture was about Session Iniciation Protocol. He showed
sip session flow example with SIP trapezoid. He also showed SIP message
format, and registration with the SIP registrar. He showed
communication with or without Proxy.
Second lecture in the week talked about SIP conferencing. He detailed
the star network that is formed while conferencing.
I looked at RFC 3665 to understand the registration process and basic
call flows.