User Manual

Virtual Channels
92 Enterasys X-Pedition User Reference Manual
Virtual Channels
A virtual channel is a point-to-point connection that exists within a physical connection. You can
create multiple virtual channels within one physical connection, with each virtual channel having
its own traffic profile. The name “virtual” implies that the connection is located in silicon instead of
a physical wire. Refer to Creating a Service Profile Definition on page 94 for information about
defining a set of traffic parameters for a virtual channel.
Creating a Virtual Channel
To create a virtual channel, enter the following command in Configure mode:
The following is a description of the parameters used to create a virtual channel:
port <port list> This parameter identifies the ATM port as well as the virtual channel identifier
(VCI) and virtual path identifier (VPI). Specify this parameter 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 on where you want to create a virtual channel.
vpi Specifies the Virtual Path Identifier. This number identifies a particular virtual
path.
vci Specifies the Virtual Channel Identifier. This number identifies a particular
virtual channel. The combination of VPI and VCI is known as the VPI/VCI pair,
and identifies the virtual channel.
Note: Do not specify VCI numbers 0 through 31. Some protocols use these
VPI/VCI pairs for signaling purposes.
vbr Opens the VC with a default VBR service. All VCs to which you will apply a VBR service
must be created with this option for traffic shaping to behave properly. If you specify the
'vbr' option, you may apply only VBR services to the VC. If you do not specify the 'vbr'
option, you may apply only UBR and CBR services to the VC.
Note: Traffic on ATM Virtual Circuits configured with a Variable Bit Rate (nrt-vbr or rt-vbr)
traffic descriptor will not obey the configured traffic descriptor's parameters. ATM
policing mechanisms will drop nonconforming ATM cells.
Creates a virtual channel. atm create vcl port <port list> [vbr]