Siqura C-60 E-MC, User Manual, Page: 132 / 142

Siqura C-60 E-MC
Page 126
SSM is implemented on the encoder side, by having the unit transmit a multicast stream to the
232.x.x.x group (the range assigned to SSM) via RTSP. The Session Description Protocol (SDP)
file generated by the RTSP server includes additional information containing the source IP (S)
and the multicast group (G). The RTSP client in the decoder can then issue an IGMP join message
containing S and G. The intermediary routers can use this information to determine the shortest
path between encoder and decoder to route the multicast stream. On the decoder side, the user
requests a stream from the encoder, using an SSM aware RTSP client (such as VLC, for
example).
For more information on source-specific multicast, refer to the following.
http://tools.ietf.org/pdf/rfc4607.pdf
http://tools.ietf.org/pdf/rfc4570.pdf
ftp://ftp.rfc-editor.org/in-notes/pdfrfc/rfc3569.txt.pdf
http://www.rfc-editor.org/rfc/pdfrfc/rfc5760.txt.pdf
11.2 Multi-Unicasting
As an alternative to multicasting, the C-60 E-MC features 'multi-unicasting', that is - sending out
up to 3x3 independent copies of video, and 3 of audio, data and contact closure streams. If the
bit rates selected are moderate, it may be more convenient to use this mechanism instead of
multicasting, even though the network gets more signal to carry from the encoder.
When such a destination is removed, the source also stops sending the corresponding stream. If
the input channel of a destination is disabled without disabling the source, source transmission
will be throttled, but not disabled (this behavior is selectable through the FloodGuard settings).
The source downsizes the stream by sending empty UDP packets until a wake-up call is received.
The empty packets, of course, carry the relevant IP/port information.
11.3 Port Numbers
A valid UDP port number in a Siqura A-, C-, S-, and V-series system is an unsigned 16-bit integer
between 1024 and 65536. Generally, you do not need to select other than the default receiver
port numbers as given in the MIB (Management Information Base). If you want to change these
receiver port numbers for some reason, use even numbers. A given receiver port number N is
associated with the port number N+1, through which control information is returned to the
source.
Eligible port numbers in general are within the range indicated above, with some exceptions.
Those within the 3000-10000 range are reserved and/or hard-coded, or may become reserved,
so only 10000-65535 are generally safe. Default port numbers (used by receivers) are shown in
the following table.
General Example
Video 50xxx Video 50010
Audio 51xxx Audio 51010
Data 52xxx Data 1 52010 (RS-4xx)
Data 2 52020 (RS-232)
CC 53xxx CC 1 53010
CC 2 53020
Default port numbers
Siqura MX applications using automatic port number allocation may use 55000 and up.