Alcatel-Lucent 7342 - Soc Onts with CES DS1;E1 Interfaces; Clocking, Network Synchronization, and Time Calibration for CES; Figure 5-9 Business ONT Functional Block Diagram

5 — SoC based ONT functional blocks
5-10 July 2008 Alcatel-Lucent 7342 ISAM FTTU ONT R04.05.06
ONT Product Information Manual Edition 01 3FE 51892 AAAA TCZZA
5.8 SoC ONTs with CES DS1/E1 interfaces
Micro span is a product on the Litespan system, used to provide wideband services
over an Ethernet link. These services are carried across the Ethernet network. The
network aggregates the traffic, both Ethernet and PON. The CES traffic is
transmitted across a CES VLAN that is created between the 7342 ISAM FTTU and
the 7450 ESS.
The BONT supports connections for DS1 or E1 services. The CES IWF interface
provides MEF-8 packetization of DS1 or E1 traffic from the DS1/ E1 interface,
which provides two RJ-48C ports. Figure 5-9 shows the business ONT functional
block diagram.
Figure 5-9 Business ONT functional block diagram
The business ONT can terminate up to two DS1 or E1 links at the subscriber’s
premises, and performs layer 2 Ethernet packetization and de-packetization using
MEF-8 and pseudo-wire PWE3 technology. TDM traffic is encapsulated using
MEF-8 packetization before being transported across the GPON as layer 2 Ethernet.
Structured, unstructured, and fractional DS1 or E1 are supported.
The CES IWF packetizes DS1 or E1 traffic received at the RJ-48C port before it is
multiplexed with other Ethernet layer 2 data packets for transport upstream on the
GPON. MEF-8 is the packet payload format used. The packetization is removed
before downstream DS1 or E1 traffic from the GPON is sent to the DS1 or E1 lines
at the subscriber side.
Clocking, network synchronization, and time calibration for CES
The business ONT can use one of two clocking sources for CES: a derived GPON
clock or a local oscillator. When the system clock for CES is derived from the
GPON, the upstream P-OLT locks to the BIT clock and supplies the ONT with an
Ethernet clock that is traceable to a network timing reference. The supplied Ethernet
clock is used for differential clock recovery and for timing the upstream pseudo-wire
MEF-8 packet streams in the absence of a valid TDM recovery clock. The local
oscillator is only used if adaptive mode is selected.
Power
Converter
GPON
Ethernet (1)
RJ-11
RJ-45
RJ-48C
F-type
coaxia
l
Video amplifier
Triplexer
1888
3
POTS (8)
External
DSP
SOC
DS1/E1 (2)
CES
IWF