[h323plus] Multicast

Troy blindDrop at shaw.ca
Thu Aug 28 00:56:53 EDT 2008

Thanks for your input Marcos.

I have already looked at OpenMCU but it seems to be too different from
what is required for a decentralised conference.  As I recall, the
signalling involved in OpenMCU is the default behaviour of the base
classes for the most part.  It wasn't clear to me how to change the
signalling to identify distributed multicast but I'm still researching

But the biggest question I have is how difficult it will be to add
multicast capability to the library.  Is it as simple as joining a
multicast group if the network address is a multicast address and having
everything else basically just work (same code to send/receive on an
established multicast socket as for a UDP unicast socket) or is there
more to it than that... maybe some additional management associated with
H.323/H.245/H225.0/???? under this circumstance?

So nobody else can provide any pointers/opinions?


On Wed, 2008-08-20 at 09:26 -0300, Marcos Fábio Jardini wrote:
> Hi Troy
> Try see "http://www.packetizer.com/ipmc/h323/whatsnew_v4.html -
> Multiplexed Stream Transmission" for some hint
> In your case each endpoint must act as a MCU, what is need is to
> investigate the recomendations and see if more than one of end-point
> can signal herselfs as MCU capanility
> See the OpenMCU implementation as the begining point of how implement
> the  mcu capable signaling.
> Another good point is our CVS
> (http://sourceforge.net/cvs/?group_id=194599) there you can see other
> reference implementations, like NAT/Firewall Traversal etc.
> PS.: is not necessary to create a 'trash' account for this group, is
> not a group with many messages and we have no problems with spam
> 2008/8/18 Junk-Mail Wastebasket <blindDrop at shaw.ca>
>         Greetings H323Plus devs.
>         I have need of an ability to support a conference where each
>         end-point can/will manipulate the audio stream coming from
>         every other end-point based on some data associated with each
>         end-point.  To me, it seems like each end-point should
>         multicast the audio stream and possibly the data that each
>         other end-point will use to modify the audio stream.  Each
>         end-point should listen for multicasts associated with the
>         conference and modify and mix the streams as required based on
>         the data.  From my internet searches, this seems to be more or
>         less the classic decentralised/distributed multipoint
>         conference.
>         I have attempted to search the mailing list archives and code
>         for how to do this with H323 Plus and have found that the
>         capability appears to be lacking.  Although I am willing to
>         work on developing this capability, I am far from expert on
>         H323 (Plus or otherwise) or VoIP and would need some strong
>         pointers from those of you who are expert.  I would appreciate
>         some input on how best to proceed to get the functionality for
>         which I'm looking.
>         Your suggestions would be most welcome,
>         Troy.
> -- 
> -----
> Jogue RPG, alimente o lado criativo!

More information about the h323plus mailing list