SDP Message Details

v=0
o=Tesla 289084526 28904526 IN IP4 lab.high-voltage.org
s=-
c=IN IP4 100.101.102.103
t=0 0 m=audio 49170 RTP/AVP 0
a=rtpmap:0 PCMU/8000

Version number (ignored by SIP)
Origin (not used by SIP)
Subject (ignored by SIP)
Connection Data

connection: network (IN == Internet), Address type (IPv4), and Address

Time (ignored by SIP): start stop
Media (type, port, RTP/AVP Profile)
Attribute (profile, CODEC, sampling rate)

Transcript

[slide193] But the protocol itself is really, really simple. In a message like that. V equals zero. O equals that. S equals minus. C equals that. V is for version number. O for origin. S for subject. C for connection. It has the form IN means Internet time which gives a start and stop media which gives a type, a port, and an RTP audio visual profile and then attribute which tells us for that profile which CODEC and which sampling rate to be used. Not very human readable but happily machine parsable.