User Manual

Cell Scrambling
96 Enterasys X-Pedition User Reference Manual
Applying a Service Profile Definition
To apply a service profile definition to a virtual channel, virtual path, or an ATM port, enter the
following command in Configure mode:
The following is a description of the parameters used to apply a service profile definition:
service <string> Specifies the name of the service profile definition which you want to apply. The
maximum length is 32 characters.
port <port list> Specifies the port, in the format: media.slot.port.vpi.vci
media Specifies the media type. This is at for ATM ports.
slot Specifies the slot number where the module is installed.
port Specifies the port number.
vpi Specifies the Virtual Path Identifier. This parameter identifies the virtual path.
This parameter is optional.
vci Specifies the Virtual Channel Identifier. This parameter identifies the virtual
channel. This parameter is optional.
An important concept when applying service profile definitions is the concept of inheritance. Since
a service profile definition can be applied to a virtual channel, virtual path, or an ATM port, the
actual connection can inherit the service profile definition from any one of the three. The virtual
channel will inherit the service profile definition that is directly applied on it. If no service profile
was applied to the virtual channel, the connection will inherit the service profile applied to the
virtual path. If no service profile definition is applied to the virtual path, the connection will inherit
the service profile applied to the ATM port. If no service profile is applied to the port, the default
service class UBR is applied.
Cell Scrambling
Cell scrambling is useful for optimizing the transmission density of the data stream. Since all
transmissions use the same source clock for timing, scrambling the cell using a random number
generator converts the data stream to a more random sequence. This ensures optimal transmission
density of the data stream.
Enabling Cell Scrambling
This command allows you to enable cell scrambling for the PDH (plesiochronous digital hierarchy)
physical (PHY) interfaces available on the ATM line card, such as T1, T3, E1, and E3 PHYs.
Applies a service profile definition. atm apply service <string> port <port list>