Avaya M770 Manual Do Utilizador
Chapter 6
Managing Virtual Ports
64
Avaya M770 ATM Switch User’s Guide
Configuring Virtual Ports
Creating a virtual port
Note:
Before you can create a new virtual port you must assign a VPI range. To do
this you must first reduce the VPI range of the root virtual port. For more
information about setting the VPI range for a virtual port, see Setting Virtual Port
Parameters later in this chapter on page 69.
information about setting the VPI range for a virtual port, see Setting Virtual Port
Parameters later in this chapter on page 69.
To control shaping use the
vport create
command.
Traffic shaping for DS3 virtual ports
The M4-DS3 module supports traffic shaping (rate limit shaping) on its virtual
ports. You can use shaping only on non-root virtual ports.
All aggregated traffic (SVCs, PVCs etc.) going out of the vport is shaped to the Peak
Cell Rate (PCR) which is configured by the user for that vport. Rate limit shaping
means that the DS3 module will adjust the transmitted traffic to a rate no higher
than the user defines as the PCR for the vport. The DS3 module uses a 256k buffer to
allow bursty traffic to be accumulated in the switch and then be sent out later.
In order to control shaping you use the
ports. You can use shaping only on non-root virtual ports.
All aggregated traffic (SVCs, PVCs etc.) going out of the vport is shaped to the Peak
Cell Rate (PCR) which is configured by the user for that vport. Rate limit shaping
means that the DS3 module will adjust the transmitted traffic to a rate no higher
than the user defines as the PCR for the vport. The DS3 module uses a 256k buffer to
allow bursty traffic to be accumulated in the switch and then be sent out later.
In order to control shaping you use the
vport create
command. The
bandwidth
parameter defines the Peak Cell Rate (PCR) allowed on a vport and is
defined in Cells Per Second (Cells/sec).
If you do not define a bandwidth value, then a default rate is assigned to that vport.
The default rate is calculated as follows: the actual maximum bandwidth of the port
divided by the maximum number of vports that can be defined on a port. The actual
maximum bandwidth of a ports takes into account the overhead associated with the
different cell mappings (ADM/PLCP). The maximum number of vports per port
depends on the number of vpi bits configured for the module.
For example, if the number of VPI bits is 3 and we are using ADM then the default
If you do not define a bandwidth value, then a default rate is assigned to that vport.
The default rate is calculated as follows: the actual maximum bandwidth of the port
divided by the maximum number of vports that can be defined on a port. The actual
maximum bandwidth of a ports takes into account the overhead associated with the
different cell mappings (ADM/PLCP). The maximum number of vports per port
depends on the number of vpi bits configured for the module.
For example, if the number of VPI bits is 3 and we are using ADM then the default
Command:
M4-DS3s8:/>vport create <vport id> <VPI> [<bandwidth>]
Example:
M4-DS3s8:/>vport create 1.2.3 4 2358
Parameters:
<vport id>
The new virtual port identifier is an integer which isn’t yet used to
represent a virtual port on this physical port. The virtual port is in
the form <slot>.<port>.<virtual port number>.
represent a virtual port on this physical port. The virtual port is in
the form <slot>.<port>.<virtual port number>.
<vpi>
The virtual path to be associated with this virtual port. This virtual
path must already exist on physical port <slot>.<port>
path must already exist on physical port <slot>.<port>
[<bandwidth>]
Applicable for DS3 modules only. An optional parameter to set
the bandwidth pool. The default value is root max bandwidth/
max number of vports per port. The bandwidth is measured in
CPS.
the bandwidth pool. The default value is root max bandwidth/
max number of vports per port. The bandwidth is measured in
CPS.