SIP Call Setup

SIP Call Setup†

SIP Call Setup - when B has not registered
SIP Call Setup - when B has not registered

† From the lecture notes “SIP Tutorial: Introduction to SIP” by Henry Sinnreich and Alan Johnston, formerly at http://smuhandouts.com/8393/SIPTutorial.pdf

Transcript

[slide140] So, call set up, the INVITE goes out, the DNS query happens based on the SIP URI, we learn an address of an inbound proxy. And we got to the location server. Oops! He isn't available yet. Because they have not registered.