Differences In Sonet/Sdh Standards; Table 16: Differences Between Sonet And Sdh Standards - Alcatel-Lucent 7750 SR OS Interface Configuration Manual

Port Features

Differences in SONET/SDH Standards

SONET and SDH standards are slightly different with respect to the behavior of K1 and K2 Bytes.
Table 16

Table 16: Differences Between SONET and SDH Standards

SONET/SDH standards
use different codes in the
transmitted K1 byte (bits 1-
4) to notify the far-end of a
signal fail/signal degrade
detection.
SONET systems signal the
switching mode in bits 5-8
of the K2 byte whereas
SDH systems do not signal
at all.
Page 52
depicts the differences between the two standards.
SONET
1100 for signal fail
1010 for signal
degrade
1101 unused
1011 unused
101 for bi-dir
100 for uni-dir
7750 SR OS Interface Configuration Guide
SDH
1101 for signal fail
1011 for signal degrade
1100 unused
1010 unused
Not used. 000 is signaled
in bits 5 to 8 of K2 byte
for both bi-directional as
well as uni-directional
switching.
Comments
None
SONET systems raise a mode
mismatch alarm as soon as a
mismatch in the TX and RX
K2 byte (bits 5 to 8) is
detected.
SDH systems do not raise the
mode mismatch alarm.