Alcatel-Lucent 7330 Product Information Manual page 39

FEC
Forward Error Correction (FEC) is used by the GEM transport layer between the
ONTs and an P-OLT, and is based on transmitting the data in an encoded format. The
encoding introduces redundancy, which allows the decoder to detect and correct the
transmission errors.
Fragmentation
Fragmentation occurs when a packet received at the ONT is larger than the maximum
transmission grant size. The ONT segments the packet and sends the segments in
multiple GEM frames over the GPON to the LT card at the P-OLT. The packets are
then reassembled at the LT card. Fragmentation occurs between the ONT and the
P-OLT in the upstream direction.
AES
The SSH transport layer provides authentication, encryption, and integrity.
Encryption is provided by a public-private key exchange to negotiate a shared
session secret between the ONT and the P-OLT: the symmetric key for AES. The
connection layer provides multiplexing of different streams over the transport layer.
AES is enabled on a per-service level during service configuration at the P-OLT
using TL1.
Alcatel-Lucent 7330/7302 ISAM FTTN R04.02.41
3FE 54017 AAAA TCZZA
Note —
FEC is not supported on the following types of ONTs:
•
I-020E-B
•
I-020E-H
•
I-220E-A
•
O-421E-B
December 2010
Edition 01 ONT Product Information Guide
1 — ONT and MDU overview
1-15