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24
Setting the Interfaces - SDH Operation
Setting THRU Mode
Setting THRU Mode
Description
THRU mode is used to non-intrusively monitor SDH lines where no protected monitor
points are available. To enable THRU mode select the
page. Select SIGNAL RATE before selecting THRU mode.
The entire frame can be errorred at a user defined rate if PAYLOAD OVERWRITE
and SOH+POH CHANNEL OVERWRITE are both set to
. If either overwrite is
enabled the ENTIRE FRAME ERROR RATE function is disabled.
There are nominally three modes of operation as follows:
1. Transparent mode: This is the case when the PAYLOAD OVERWRITE field is set
to OFF. The received signal is passed through the transmitter completely unchanged.
The figure below illustrates the settings for this mode.
2. Hitless THRU Mode: This mode enables you to change the channel under test and
the payload mapping without causing errors in the line signal or any other payload
channel, or having to switch out of THRU mode. When you select a Payload Overwrite
choice (other than OFF) an additional field is displayed which allows you to enable/
disable Payload Overwrite. If Payload Overwrite is disabled the instrument remains
transmitting while you select another channel/tributary (see figure on next page). In
this mode any Section or Line B1, B2 BIP errors are recalculated before transmission.
TRANSMIT
MAIN SETTINGS
OFF
SONET_Usr.bk Page 24 Wednesday, December 13, 2000 11:11 AM
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