Connected: An Internet Encyclopedia
6.6 APP: Application-defined RTCP packet
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6.6 APP: Application-defined RTCP packet
6.6 APP: Application-defined RTCP packet
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|V=2|P| subtype | PT=APP=204 | length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SSRC/CSRC |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| name (ASCII) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| application-dependent data ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The APP packet is intended for experimental use as new applications
and new features are developed, without requiring packet type value
registration. APP packets with unrecognized names should be ignored.
After testing and if wider use is justified, it is recommended that
each APP packet be redefined without the subtype and name fields and
registered with the Internet Assigned Numbers Authority using an RTCP
packet type.
- version (V), padding (P), length:
-
As described for the SR packet (see Section 6.3.1).
- subtype: 5 bits
-
May be used as a subtype to allow a set of APP packets to be
defined under one unique name, or for any application-dependent
data.
- packet type (PT): 8 bits
-
Contains the constant 204 to identify this as an RTCP APP
packet.
- name: 4 octets
-
A name chosen by the person defining the set of APP packets to
be unique with respect to other APP packets this application
might receive. The application creator might choose to use the
application name, and then coordinate the allocation of subtype
values to others who want to define new packet types for the
application. Alternatively, it is recommended that others
choose a name based on the entity they represent, then
coordinate the use of the name within that entity. The name is
interpreted as a sequence of four ASCII characters, with
uppercase and lowercase characters treated as distinct.
- application-dependent data: variable length
-
Application-dependent data may or may not appear in an APP
packet. It is interpreted by the application and not RTP itself.
It must be a multiple of 32 bits long.
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Connected: An Internet Encyclopedia
6.6 APP: Application-defined RTCP packet