There is a known issue with GeoVision cameras. Some of them do not properly send the RTP end of packet bit per the RTP specification. This is needed by Wowza Server.
The specification is here:
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Marker bit (M): 1 bit
Set for the very last packet of the access unit indicated by the
RTP timestamp, in line with the normal use of the M bit in video
formats, to allow an efficient playout buffer handling. For
aggregation packets (STAP and MTAP), the marker bit in the RTP
header MUST be set to the value that the marker bit of the last
NAL unit of the aggregation packet would have been if it were
transported in its own RTP packet. Decoders MAY use this bit as
an early indication of the last packet of an access unit, but MUST
NOT rely on this property.
Informative note: Only one M bit is associated with an
aggregation packet carrying multiple NAL units. Thus, if a
gateway has re-packetized an aggregation packet into several
packets, it cannot reliably set the M bit of those packets.
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We rely on this marker bit being set properly. It would be best to work with the camera vendor to get this addressed.