System information

FCD 901 48
Issue R2A, 07.2009
XMP1 Release 5.5 System Description
Suppressing the clock priority (at F1in)
Page 2-24 Proprietary Information Aastra
2.3.6.8 Suppressing the clock priority (at F1in)
Using info no. 10 it is possible to suppress the evaluation of the clock priority
at F1in of the port interface.
Info no. 10 = 0:
The clock priority is evaluated at F1in of the port interface (default setting).
Info no. 10 = 1:
The clock priority is not evaluated at F1in of the port interface.
Example 1
The following example shows an application with the clock priority being
suppressed at F1in.
In this example, transmission between the two XMP1 nodes takes place via
a third-party unit (e.g. PCM FXE). The system channel is re-routed via
channel 29.
Thus, the clock priority is also transmitted in channel 29.
Thus, for passing the third-party unit, info no. 10 must be set to "1" for the
port from which the third-party unit recovers the clock.
In case of a drop including a PCM30 FXE unit, this is normally port 1.
Figure 2.10: Suppressing the clock priority (at F1in)
T3in = Priority 1
XMP1 node 1
Third-party node 2
XMP1 node 3
P1
FXE
XMP1 node 1:
System channel re-routed via
Clock priority suppressed at F1in.
Third-party node 2:
Fixed clock recovery at port 1
FXE
P1
P1
P3
P1
P3
channel 29