Hardware Interface
Line Interface
Centillion 1200N ATM Switch User Manual
6-3
NTP 297-8103-903
SONET OC3/SDH STM-1 Frame Format
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For public network UNI and private network UNI/NNI
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Physical layer: SONET PMD
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Optical fiber (multi mode/single mode), UTP5
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Line coding: NRZ
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Data rate/line rate: 155.52 Mbps
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Cell rate: 155.52 × 260/270 = 149.76 Mbps
Figure 6-3: SONET OC-3/SDH STM-1 Frame Format
2 7 0 B y te s
9 B y te s
A 1 ,A 2
:F ra m e a lig n m en t
B 1
:B IP -8
B 2
:B IP -2 4
C 1
:S T M fram e id e n tific atio n
D 1 -D 1 2
:D ata co m m u n ic atio n ch an n e l
E 1 ,E 2
:O rd er w ire
F 1
:U se r ch a n n e l
K 1
:C h a n g e-o v er co n tro l
K 2
:C h a n g e-o v er co n tro l,A IS /R D I
Z 1
:R e se rv ed
Z 2
:F E B E
A 1
:B its a ctiv e in U N I
P a th Tra ce
B IP -8
P a th Id e n tifie r
E rro r R e p o rt
U ser C h a n n el
H ea d e r C ell In d ic ato r
R e se rv ed
R e se rv ed
R e se rv ed
J1
B 3
C 2
G 1
F 2
H 4
Z 3
Z 4
Z 5
E 1
F 1
D 1
D 2
D 3
K 1
D 4
D 5
D 6
D 7
D 8
D 9
D 1 0
D 11
D 1 2
Z 1
B 1
A 1 A 1 A 2 A 2 A 2 C 1 C 1 C 1
A U -4 p o in te r
B 2
Z 1
B 2 B 2
K 2
Z 1 Z 2 Z 2 Z 2 E 2
A 1