See RFC1889:
marker (M): 1 bit
The interpretation of the marker is defined by a profile. It is
intended to allow significant events such as frame boundaries to
be marked in the packet stream. A profile may define additional
marker bits or specify that there is no marker bit by changing
the number of bits in the payload type field (see Section 5.3).
:
5.3 Profile-Specific Modifications to the RTP Header
The existing RTP data packet header is believed to be complete for
the set of functions required in common across all the application
classes that RTP might support. However, in keeping with the ALF
design principle, the header may be tailored through modifications or
additions defined in a profile specification while still allowing
profile-independent monitoring and recording tools to function.
o The marker bit and payload type field carry profile-specific
information, but they are allocated in the fixed header since
many applications are expected to need them and might otherwise
have to add another 32-bit word just to hold them. The octet
containing these fields may be redefined by a profile to suit
different requirements, for example with a more or fewer marker
bits. If there are any marker bits, one should be located in
the most significant bit of the octet since profile-independent
monitors may be able to observe a correlation between packet
loss patterns and the marker bit.
ITU G.729 might hold further information.
Regards
Anders
_____
Från: wireshark-users-bounces-IZ8446WsY0/***@public.gmane.org
[mailto:wireshark-users-bounces-IZ8446WsY0/***@public.gmane.org] För Boaz Galil
Skickat: den 29 juli 2009 17:37
Till: Community support list for Wireshark
Ämne: [Wireshark-users] What does it mean the "Mark" string under theinfo in
RTP packets?
Dear Experts,
I am reviewing G729 packet stream. I have noticed that I have lots of
packets that have the string "Mark" in the info field.
Guy/or any other expert - can you please share some information about the
"Mark" string?
Thanks in advance,
--
Boaz.