16
Central Switching Module PTN-CSM310-A/PTN-CSM540-A
Release 03 05/2020
The CSM cleans up and redistributes this clock over the entire node to all the interface slots.
If multiple recovered clocks are available in a node, the CSM will select the best available clock.
SyncE Support: Verify the ‘
PROTOCOL AND FEATURE SUPPORT MATRIX
’ in Ref. [2Net] in
Table 2 to find out which IFMs support this feature;
How the best available clock is determined must be configured in HiProvision:
Ethernet services: the best available clock can be determined dynamically via SSMs (=Sync
Status Message) or statically via a dedicated interface port. SSMs are transmitted to
downstream neighbor nodes to report the stability and accuracy of its distributed clock;
Circuit Emulation Services: the best available clock must be assigned statically to a
dedicated interface port;
NOTE:
The IFM manual indicates whether an IFM port can participate in SyncE;
NOTE:
The CSM management port does not participate in the SyncE clock distribution;
NOTE:
If no distributed clock is available in a node, the node falls back to the local clock
oscillator on the CSM;
NOTE:
The figure below is an example of the CSM310-A. It is similar for the CSM540-A.
Figure 5
SyncE Clock Recovery
N
S
M
P
S
U
-
1
P
S
U
-
2
I
F
M
-
1
I
F
M
-
2
I
F
M
-
3
I
F
M
-
4
I
F
M
-
5
I
F
M
-
6
I
F
M
-
7
I
F
M
-
8
I
F
M
-
9
C
S
M
-
1
C
S
M
-
2
4-GC-LW
Data1
Recovered
Clock
(SyncE)
CSM310-A
Distributed
clock
Data1
Data2
Data2
4-E1-L
Data1
Recovered clock
from Data1
Distributed clock
data switching
clock selection &
redistribution
I
F
M
-
10