Line Interface
Hardware Interface
6-2
Centillion 1200N ATM Switch User Manual
NTP 297-8103-903
Line Interface
Provided below is an outline of the line interface specifications of the ATM Switch:
SONET OC-12/SDH STM-4 Frame Format
■
For public network UNI and private network UNI/NNI
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Physical layer: SONET PMD
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Optical fiber (single mode)
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Line coding: NRZ
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Data rate/line rate: 622.08 Mbps
■
Cell rate: 622.08 × 1040/1080 = 599.04 Mbps
Figure 6-2: SONET OC-12/SDH STM-4 Frame Format
9R
O
W
S
MS
O
H
AU
PO
IN
T
E
R
RS
O
H
1 2B ytes
1 2B ytes
1 2B ytes
4 B y te s
1 08 0B ytes
1 04 4B ytes
8 B y te s
4 B y te s
1 04 4B ytes
S T M -4 fra m e
V C -4-4C
H 1 * :1 0 0 1 S S 11 (S S b it,in c lu d in g H 1 , is s et 1 /O O C 1 2 = " 0 0 " S T M -4 = "1 0 " )
H 2 * :11111111
C 1 * :U n as sig n e d b y te(1 0 1 0 1 0 1 0 = N T T sp ecific atio n (S T M -4 ) fix ed )
:U n a ss ig n ed b y te(A L L "0 " ) < O C 1 2 sp ec ificatio n fix ed >
A fte r 2 b y te s o f E 1 ,E 2 ,D 1 -D 1 2 ,an d Z 1
Z 2 # 1 ,Z 2 # 2 ,Z 2 # 4 -Z 2 # 1 2 ,J 1 ,F 2 ,Z 3 -Z 5 :A L L " 1 "
F IX E D S T U F F :A L L "1 "
D 10
B 1
D 1
H 1
H 1*
H 1*
B 2
B 2
D 7
Z 1
Z 1
D 4
A 1
A 1
B 2
E 1
D 2
H 2
H 2*
H 2*
Z 2
Z 2
D 5
D 8
D 11
Z 1
A 1
A 2
A 2
K 1
H 3
D 9
H 3
H 3
H 3
H 3
H 3
Z 2
E 2
A 2
C 1
C 1
C 1
C 1
C 1*
C 1*
F 1
D 3
K 2
D 6
D 12
J1
B 3
C 2
G 1
F 2
H 4
Z 3
Z 4
Z 6
F IX E D
S T U F F
V C -4-4C PAY L O A D
