PLANET EPL-1000 - Manual (Page 76)

General Query Received from EPON
If any groups are present on either of the ONUs UNI ports, the ONU will start a count down
timer that is equal to: [provisioned robustness count] * [Max Response Time specified in
query]. If a report is not received within this interval, for any group joined on either of the
ONU’s UNI ports, the group will be removed from the ONU’s multicast forwarding table.
Group Specific Query Received from EPON
If any groups are present on either of the ONUs UNI ports, the ONU will start a count down
timer that is equal to: [provisioned GSQC] * [Max Response Time specified in query]. If a
report is not received within this interval, for the specified group joined on either of the
ONU’s UNI ports, the group will be removed from the ONU’s multicast forwarding table.
„ Behavior of OLT
By default the OLT shall block all IGMP multicast data traffic preserving the bandwidth of
the PON and user network. When an STB or other host attached to one of the several
ONU’s UNI ports requests to join a multicast group, the query is snooped by the OLT’s CPU,
and conditionally forwarded upstream.
Report Received from Logical Link
If no host is joined to the group on the attached interface, the OLT will install a new rule to
forward the group to one of the several IGMP multicast data FIFOs. The OLT will pick the
FIFO with least groups joined.
„ Group Insertion Process:
Leave Received from Logical Link
The OLT will issue LMQC GSQs, spaced by LMQI until one of the following two events
occurs (whichever occurs first).
1. 1 or more reports are received upstream for the group specified in the leave message.
2. No report is received after LMQI units from the time that the final LMQ was issued.
In case (1), the load balancing algorithm will be applied as described above. In case (2) the
group will be removed from the forwarding table, and the OLT will transmit a leave message,
with the provisioned source IPv4 Address, from the OLT’s NNI.
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