10
GPON ONT STANDAR
The communication between client equipment (ONT) and the ISP access routers (MAN edge) is made by an optical fiber-based passive architec-
ture (ITU-T G.984 Recommendation). The GPON network acts as a Layer 2 Ethernet metropolitan network. Access network assures and controls
the media (MAC) communication through a TDMA scheme, introducing GEM (GPON Encapsulation Method) in between to adapt TDM layer to
Ethernet.
The used protocol stack is shown in Figure 2-5.
IP
ETHERNET
GEM
TDM/TDMA
Figure 2-5: Stack of protocols for GPON architecture
Several transmission containers (T-CONT) are assigned to each user. Each T-CONT has an associated GEM port and each GEM port has a VLAN
identifier and an 802.1p priority level.
The ONT classifies the traffic depending on the VLAN and the marked priority, and routes it over the corresponding T-CONT/GEM port. Thus for
frame multiplexing, GEM and T-CONT ports are used for uplink while the downlink only use the GEM ports feature.
The CPE architecture is shown in Figure 2-6.
Figure 2-6: CPE architecture
Internet access is provided through the Home Gateway (HG) to obtain a public Internet IP.
The home gateway allocates a private IP address to each client through DHCP, making the addresses conversion through NAT for Internet output.
The home gateway establishes PPPoE session with the ISP network, which authenticates the user for Internet access. The user must be a service
subscriber and the service must be provisioned at the OLT where the ONT is connected to.
Содержание 769503
Страница 1: ...GPON ONT STANDARD EN User s Manual w w w t e l e v e s c o m Ref 769503 ...
Страница 2: ......
Страница 5: ...EN 5 ...
Страница 36: ...36 GPON ONT STANDAR ...
Страница 39: ......
Страница 40: ......