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 spe cifications of the ATM Switch:

SONET OC-12/SDH STM-4 Frame Format

■For public network UNI and private network UNI/NNI
■Physical layer: SONET PMD
■Optical fiber (single mode)
■Line coding: NRZ
■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

9ROWS
MSOH AU
POINTER RSOH
12Bytes 12Bytes 12Bytes
4Bytes
1080Bytes
1044Bytes
8Bytes
4Bytes 1044Bytes
STM-4 fram e
VC-4-4C
H1*:1001SS11 (SS bit,including H1, is set 1/O OC12="00" STM-4="10")
H2*:11111111
C1*:Unassigned byte(10101010=NTT specification (STM-4) fixed)
:Unassig n ed b y te (A LL"0 " ) < O C 12 spe c ific at ion f ix ed >
After 2 bytes of E1,E2,D1-D12,and Z1
Z2#1,Z2#2,Z2#4-Z2#12,J1,F2,Z3-Z5:ALL"1"
FIXED STUFF:ALL"1"
D10
B1
D1
H1 H1* H1*
B2 B2
D7
Z1 Z1
D4
A1 A1
B2
E1
D2
H2 H2* H2*
Z2 Z2
D5
D8
D11
Z1
A1 A2 A2
K1
H3
D9
H3 H3 H3 H3 H3
Z2 E2
A2 C1 C1C1 C1 C1* C1*
F1
D3
K2
D6
D12
J1
B3
C2
G1
F2
H4
Z3
Z4
Z6
FIXED
STUFF VC-4-4C PAYLOAD