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LTP-8X optical line terminal
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A C-VLAN is used between ONT and service routers (BRAS, VoIP SR) that encapsulate services for one
subscriber (one ONT), such as VoIP, Internet, and IPTV unicast. An S-VLAN that is global for all
subscribers (ONTs) is used for the TR-69 management service. Corresponding GEM ports are created for
every OLT service between ONT and OLT. A dedicated MC-VLAN is used for multicast transmissions.
OLT casts C-VLAN (for VoIP, Internet, and IPTV unicast) or S-VLAN (for TR-069) for every service into a
corresponding U-VLAN. ONT associates the U-VLAN with corresponding ONT interfaces or program
modules. For example, a TR-069 service is associated with a TR-69 client with the help of a
corresponding interface. VoIP, Internet, and IPTV unicast services can operate in the "router" or "bridge"
modes depending on ONT configuration. The chart shows all services configured in the "router" mode.
Broadcast and unknown unicast traffic is transmitted in this model by replicating a corresponding packet
(broadcast or unknown unicast) to OLT. C-VLAN replicates services to all associated GEM ports and at
the same time translates data to corresponding U-VLAN for each service. TR-069 service is replicated
between corresponding GEM ports of all subscribers (ONT). Thus, the model implements "VLAN for
Subscriber" for VoIP, Internet, and IPTV unicast services, but uses "VLAN for Service" for TR-069 service.
