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LTP-8X optical line terminal
19.3
Model 2
Consider a model 2 implementation example. The chart of this service model is shown in Fig. 19.4.
Fig. 19.4. Service Model 2 Chart
A S-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-069 management service. Corresponding GEM ports are created
for every OLT service by LTP-8X between ONT and OLT. A dedicated MC-VLAN is used for multicast
transmissions.
VoIP, Internet, and IPTV unicast services are associated with C-VLAN in ONT. The TR-069 service is
associated with S-VLAN in ONT. ONT casts C-VLAN (for VoIP, Internet, 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-069 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.
All broadcast and unknown unicast traffic is redirected to a dedicated broadcast GEM port in this model.
Broadcast and unknown unicast packets are sent to C-VLAN (for VoIP, Internet, and IPTV unicast
services) in ONT. These packets are replicated for all services in ONT with simultaneous transmission to
U-VLAN. Broadcast and unknown unicast packets of the TR-069 service are sent to S-VLAN in ONT and
then are transmitted to U-VLAN.
In general, the model is similar to model 3 except the one thing: transmission of C-VLAN to U-VLAN is
performed on the OLT side; VoIP, Internet, and IPTV unicast traffic comes in U-VLAN to ONT.