Plexus 9000 Planning and Engineering Guide
DS3 ATM Network Access Module
Section 130-120-800
Issue 1, April 23, 2004
Telica, Inc.
5-199
5.18.3 Theory
of
Operation
The DNA receives DS-3 frames via the DS-3 rear module and passes them
to the framers. The framer “unframes” the data, and hunts for ATM cells
embedded in the payload of the DS-3. The ATM cells are passed along to
the APC via the Utopia bus. The APC will pass the cells along to the SF if
they match a configured VC (Virtual Circuit).
In the opposite direction, the DNA receives ATM Cells from the midplane
and forwards them to the appropriate framer over the Utopia bus. The
framer then assembles the cells into a DS-3 frame, and the encoded stream
is passed to the LIU for driving out to the DS-3 rear module and line.
Refer to
for a block diagram of the DNA module.
SERDES
to/from
SF-A
PHAZIT
Daughter Card
Eight 75 ohm Tx/Rx Pairs
MLBA and
LOCAL
CONTROL
M
I
D
P
L
A
N
E
P709-AA
04-08-02
APC
to/from
SF-B
CLOCK
CIRCUITRY
MEM BUS
CONTROLLER
PROCESSOR
and
MEMORY
AAL5
SAR
MEMORY
FRAMER
1
FRAMER
2
UTOPIA
1
LIU
2
3
4
LIU
5
6
7
LIU
8
NU
Figure 5.18-2. Octal DS-3 ATM Network Access Block Diagram
