SONETSDH

1
SONET/SDH

• SONET Synchronous Optical Network
• SDH Synchronous Digital Hierarchy
• Standard Multiplexing Format starting at 51.84
  Mbps OC-1 or STS-1
• Standard Optical Signal
• OAMP (Operations, Administration, Management
  Provisioning)
• Standard mapping format for DS1/E1, DS3 and ISDN

SONET Frame Format
Each OC-1 or STS-1 frame is 9 rows by 90 bytes.
Transport Overhead
Information Payload (SPE)
A1 B1 D1 H1 B2 D4 D7 D10 Z1
A2 E1 D2 H2 K1 D5 D8 D11 Z2
J1 B3 C2 G1 F2 H4 Z3 Z4 Z5
C1 F1 D3 H3 K2 D6 D9 D12 E2
Section Overhead
9 Rows
Path Overhead
Line Overhead
3 Columns/Bytes
87 Columns/Bytes
2
SONET Frame Format
Each OC-3 or STS-3 frame is 9 rows by 270 bytes.
Transport Overhead
Information Payload
A1 B1 D1 H1 B2 D4 D7 D10 Z1
A2 E1 D2 H2 K1 D5 D8 D11 Z2
J1 B3 C2 G1 F2 H4 Z3 Z4 Z5
C1 F1 D3 H3 K2 D6 D9 D12 E2
J1 B3 C2 G1 F2 H4 Z3 Z4 Z5
J1 B3 C2 G1 F2 H4 Z3 Z4 Z5
A1 B1 D1 H1 B2 D4 D7 D10 Z1
A1 B1 D1 H1 B2 D4 D7 D10 Z1
A2 E1 D2 H2 K1 D5 D8 D11 Z2
A2 E1 D2 H2 K1 D5 D8 D11 Z2
C1 F1 D3 H3 K2 D6 D9 D12 E2
C1 F1 D3 H3 K2 D6 D9 D12 E2
Section Overhead
Path Overhead
Line Overhead
9 Columns/Bytes
261 Columns/Bytes
SONET Frame Pointer and Alignment
SONET Frame pointer H1 and H2 specifies the
location of SPE (Synchronous Payload Envelope).
Clocking alignment is achieved by byte staffing
and dynamic adjustment of SPE frame rate.
SONET Mapping and Ring
VT Virtual Tributaries map to sub STS-1
frames. SONET Ring is used for self-healing path
switched Redundancy.