Filter
Top Products
S/UNI-QUAD
PMC-Sierra, Inc.
PM5349 S/UNI-QUAD
DATASHEET
PMC-971239 ISSUE 6 SATURN USER NETWORK INTERFACE (155-QUAD)
Proprietary and Confidential to PMC-Sierra, Inc., and for its Customers’ Internal Use
202
13.1.2
Transport and Path Overhead Bytes
Under normal operating conditions, the S/UNI-QUAD processes a subset of the
complete transport overhead present in an STS-3c (STM-1) stream. The byte
positions processed by the S/UNI-QUAD are indicated in Figure 11.
Figure 11: STS-3c (STM-1) Overhead
TRANSPORT OVERHEAD
SOH
PATH OVERHEAD
POH
A1 A1 A1 A2 A2 A2 J0 Z0 Z0
B1
H1 H1 H1 H2 H2 H2 H3 H3 H3
B2 B2 B2 K2
M1
B3
G1
C2
H4
K1
S1
Transport Overhead Bytes
A1, A2: The frame alignment bytes (A1, A2) locate the SONET/SDH
frame in the STS-3c (STM-1) serial stream.
Z0: The Z0 bytes are currently defined as the STS-3c (STM-1) section
growth bytes for SONET/SDH. Z0 bytes are not scrambled by the
frame synchronous scrambler.
B1: The section bit interleaved parity byte provides a section error
monitoring function.