U
U
s
s
e
e
r
r
M
M
a
a
n
n
u
u
a
a
l
l
station, and it is compliant with ITUT standard.
Every index is compliant with ITUT standard when OPCOM3100 change the
recovered clock reference (e.g. if there is LOS)
5.4.
Protection switch
OPCOM3100 provides 1+1 low path protection in the case that the optical fiber
is broken off, PCB is damaged or middle notes are invalid, and the protection
switch time will be less than 50ms. There are two kinds of protection switch:
automatic protection switch and force protection switch, the force protection
switch can be configured through network management. The conditions of
automatic protection switch are as follows:
Switch type
Switch conditions
Path protection
TU_AIS, TU_LOP
TU_AIS, TU-LOP are caused by:
Segment: SPI-LOS, RS LOF, MS-AIS,
MS-EXC, MS-SD (optional);
AU:AU-AIS,AU-LOP;
HP:HP-LOM, HP-EXC, HP-SD (optional);
1.
Protection switch in chain topology:
Optical
port 1
OPCOM3100
-155
work
OPCOM3100
-155
Optical
port 1
Optical
port 2
OPCOM3100
-155
protect
OPCOM3100
-155
Optical
port 2
As the above figure, in chain 1+1 path protection between two ends, there
are two transmission lines transmitting the data, and every note receives
the data twice. One of the transmitting lines is working line and the other
one is protection line. Receiving end will select a better quality signal from
the two lines. Generally the Rx data is from working line and if there is
protection switch the Rx data is from protection line. When the working line
has recovered the Rx data is from working line again.
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