Hardware Interface Line Interface

Centillion 1200N ATM Switch User Manual 6-3

NTP 297-8103-903
SONET OC3/SDH STM-1 Frame Format

For public network UNI and private network UNI/NNI

Physical layer: SONET PMD

Optical fiber (multi mode/single mode), UTP5

Line coding: NRZ

Data rate/line rate: 155.52 Mbps

Cell rate: 155.52 × 260/270 = 149.76 Mbps

Figure 6-3: SONET OC-3/SDH STM-1 Frame Format
270 Bytes
9 Bytes
A1,A2 :Frame alignment
B1 :BIP-8
B2 :BIP-24
C1 :STM fram e identification
D1-D12 :Data communication ch an ne l
E1,E2 :Order wire
F1 :User channel
K1 :Change-over control
K2 :Change-over control,AIS/RDI
Z1 :Reserved
Z2 :FEBE
A1 :Bits active in U N I
Path Trace
BIP-8
Path Identifier
Error Repo rt
User Channel
Header Cell Indicator
Reserved
Reserved
Reserved
J1
B3
C2
G1
F2
H4
Z3
Z4
Z5
E1 F1
D1 D2 D3
K1
D4 D5 D6
D7 D8 D9
D10 D11 D12
Z1
B1
A1A1A2 A2A2 C1 C1 C1
AU-4 poin te r
B2
Z1
B2B2 K2
Z1Z2 Z2 Z2 E2
A1