OLT LTP-16N, LTP-16NT. User Manual
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5
ONT configuration
5.1 Service Models
This section considers main terms and classification of service models.
5.1.1 Introduction
The service model can generally be based on one of the service principles: N-to-1, 1-to-1 and multicast. The
«VLAN for Service» (N-to-1) architecture means that a service VLAN (S-VLAN) is used to provide all users with
a certain service. The «VLAN for Subscriber» (1-to-1) architecture implies that a client VLAN (C-VLAN) is used
to provide a user with multiple services. These methods are often combined in practice and form a hybrid
model, which uses S-VLAN and C-VLAN simultaneously.
1-to-1 architecture
A separate VLAN is used for each subscriber in the C-VLAN model. In this operation scheme a channel from
the uplink port to the GEM port of the ONT, in a given S-VLAN is built for the subscriber. And all traffic
(including broadcast), goes to this GEM-port.
N-to-1 architecture
The S-VLAN model has dedicated S-VLANs for each service. Traffic is distributed among the GEM ports of the
clients, based on the MAC table. If the MAC address is not learnt, the packet is sent to the broadcast GEM-port
and replicated to all subscribers.
Multicast architecture
This architecture is similar to N-to-1, except that a dedicated multicast GEM port is used.
5.1.2 VLAN ID replacement; The concept of pon vid
The transfer of traffic from the service S-VLAN to the client C-VLAN can be done either on the OLT or on the
ONT. To configure the replacement place, use the concept of pon vid. Setting this parameter, equal to outer vid
or user vid, defines where the label replacement will take place – on OLT or ONT. The table below describes at
what stage the replacement will take place, depending on the value of pon vid.
Table 18 – VID replacement stages
The meanuing of pon vid
Where the tag is replaced
outer vid = pon vid
Replacement occurs on the ONT
user vid = pon vid
Replacement occurs on the OLT
pon vid
≠
user vid
≠
outer vid
Replacement occurs on the ONT and the OLT
Pon vid is configured in the cross-connect profile, which allows you to customize the label replacement
scheme for each service. By default, the replacement is performed on the ONT.
5.1.3 Operating principle
The model traffic concept is used for implementation of different service models in the terminal. The model is
configured in a cross-connect profile, which allows the configuration of combined circuits within a single ONT
Consider each scheme in more detail.
