IGS-900 16 DVB Tuner to IP-Out
Author: Ralf Riedel
April 15, 2018
Filename: Blankom_IGS-900-16_Tuner_to_IP_Gateway_user_manual2018-03RR
Page 27
RTP:
a part from: https://tools.ietf.org/html/rfc3550
Chapter 11:
RTP relies on the underlying protocol(s) to provide demultiplexing of
RTP data and RTCP control streams. For UDP and similar protocols,
RTP SHOULD use an
even
destination port number and the corresponding
RTCP stream SHOULD use the next higher (odd) destination port number.
For applications that take a single port number as a parameter and
derive the RTP and RTCP port pair from that number, if an odd number
is supplied then the application SHOULD replace that number with the
next lower (even) number to use as the base of the port pair. For
applications in which the RTP and RTCP destination port numbers are
specified via explicit, separate parameters (using a signaling
protocol or other means), the application MAY disregard the
restrictions that the port numbers be even/odd and consecutive
although the use of an even/odd port pair is still encouraged. The
RTP and RTCP port numbers MUST NOT be the same since RTP relies on
the port numbers to demultiplex the RTP data and RTCP control
streams.
In a unicast session, both participants need to identify a port pair
for receiving RTP and RTCP packets. Both participants MAY use the
same port pair. A participant MUST NOT assume that the source port
of the incoming RTP or RTCP packet can be used as the destination
port for outgoing RTP or RTCP packets. When RTP data packets are
being sent in both directions, each participant's RTCP SR packets
MUST be sent to the port that the other participant has specified for
reception of RTCP. The RTCP SR packets combine sender information
for the outgoing data plus reception report information for the
incoming data. If a side is not actively sending data (see
Section
6.4
), an RTCP RR packet is sent instead.
any port (even, not odd > 1024)
