Below is the paragraph excerpted from H.323 ( 8.3.3.
Media stream address distribution ).
In multicast, the multicast addresses are assigned by the MC
and distributed to the endpoints in the communicationModeCommand. It is the
responsibility of the MC to allocate and assign unique multicast addresses.
The endpoint shall signal an openLogicalChannel to the MC with the assigned
multicast address. The MC shall forward the openLogicalChannel to each
receiving endpoint. In cases where media from multiple endpoints are
transmitted on a single session (e.g. single multicast address), the MC shall
open a logical channel to each endpoint receiving media from an endpoint in
the conference.
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"Forwarding of OLC" is a little ambiguous.
1. use the same LCN ?
2. what about OLC ack?
for example, when there is a conference
composed of a MCU and Terminal A, B, and C,
only Terminal A speaks and B, C listens to
A.
then, MCU will broadcast
communicationModeCommand
that contains only one
entry
without specifying destination
and specifying the multicast address of Terminal A.
then, Terminal A will send OLC
to MCU.
From this point on, I am not sure.
Possible interpretations are..
1. MC will forward the
OLC to Terminal B and C. And The Terminal B and
C will send OLC Ack To MC.
At the time of receving OLC Ack, what
should MC do?
forward the 2 OLC Ack pdus to Terminal A
? It seems not proper..
2. MC will send the OLC Ack to Terminal A and send the
OLC to Terminal B and C. and
then OLC Ack from the
Terminal B and C will be ignored
?
3. MC will forward the OLC to Terminal B and
C, and sends OLC Ack to Terminal A
only if both Termanl B and C reply
to the OLC.
what if the new Terminal D joins
the conference ?
which is correct?