Nortel Optical Multiservice Edge 6130 Planning Manual page 68

6-8 OAM&P description
The OME6130 is capable of generating a 4.6 ppm quality clock internally. This
clock is the default synchronization reference. The OME6130 supports
synchronizing to a reference clock signal derived from the following sources
(provisioned by the user as defined by the network synchronization plan):
•
•
Table 6-3
Supported BITS signals
BITS-1-2-1
In Out
2 MHz 2 MHz
The following needs to be considered when using an external source to provide
the timing reference for the OME6130:
•
The OME6130 can identify a faulty synchronization source and switch to the
next highest quality source as defined in the input hierarchy. When all
synchronization sources (external or line) are unavailable (caused by faulty
Optical Multiservice Edge 6130
internal timing
When the internal clock is provisioned as a timing reference, the network
element goes to internal freerun mode rather than holdover mode, when the
internal clock becomes the active timing reference. See
6-9 example (a).
external timing
As shown in Figure 6-2 on page 6-9
synchronization input (ESI) port on the OAM circuit pack, the OME6130
supports external timing reference inputs. The supported BITS signals are
detailed in Table 6-3 on page 6-8
BITS-1-2-2
In
E1 (2 Mb/s) E1 (2 Mb/s)
— the external timing source and its quality
— the signal format of the external timing source (E1 or 2.048 MHz for
SDH)
— the connector type/impedance of the ESI port (120 ohm balanced or 75
ohm unbalanced)
line timing
Line timing is a clock derived from an STM-1/4 interface or an E1 port
from the 28xE1/DS1 circuit pack. See
When using line timing to provide the timing reference for the OME6130,
you may consider one of the following sources:
— one or two STM-1/4 ports on the 2x155/622M aggregate circuit pack
— one or two STM-1 ports on the 2x155M circuit pack
— any of 1, 4, 7, 10, 13, 16, 19, 22, 25, 28 E1 ports of the 28 x E1/DS1
circuit pack
NT6Q92MA Rel 1.0 Iss 1 Standard September 2006
example (b), from the external
below:
NE mode
Out
SDH
Figure 6-2 on page 6-9
Figure 6-2 on page
example (c).