Cabletron Systems MMAC-Plus SFCS-1000, Configuration Manual

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5-5
DS-3 Configuration
5.6 Configuring DS-3 Payload Scrambling
Some equipment is more sensitive than the 9A000, SFCS-200BX or the SFCS-
1000 when synchronizing with the network clock. This equipment requires a
greater transition density than the switch fabric. To work with such equip-
ment, it may be necessary to enable payload scrambling on the switch fabric.
If a DS-3 port is configured for HCS cell delineation, scrambling should be
enabled on both ends of the connection.
When payload scrambling is enabled, a scrambling function
1
is applied to the
48-byte payload of each cell transmitted. To operate with other equipment,
scrambling must be enabled on the other end of the DS-3 connection as well
so that the data is properly unscrambled. By default, scrambling is disabled.
To enable or disable scrambling on a DS-3 port, log in to AMI and enter the
following parameters:
configuration port ds3 scrambling <port> (on | off)
Using the on variable means that cell payload scrambling is enabled on the
specified port. Using the off variable means that cell payload scrambling is
disabled on the specified port. Only the payload of the ATM cells is scram-
bled.
After scrambling is enabled or disabled on a DS-3 port, the SCP immediately
puts that change into effect on that switch fabric. At the same time, that infor-
mation is entered into the configuration database file so that the change will
be put into effect every time the switch control software starts on that particu-
lar SCP.
1. Cabletron switches use the recommended self-synchronizing scrambler, x
43
+ 1.