Cabletron Systems SSIM-A2-01, Installation And User Manual

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SmartStack SSIM-A2-01/SSIM-A8-01 Console Configuration
Traffic Profiles
Traffic profiles describe the characteristics of the transmitted data. All VCCs (SVC
or PVC) created by the uplink software and the LES are assigned a traffic profile,
and for the typical ATM LAN setup, the default profile is sufficient.
However, under certain circumstances it may be necessary to change the traffic
profiles and their usage. This can often be the case with ATM WAN connections,
where bandwidth is pre-configured and/or priced, or where multiple switches using
multiple line-speeds (for example 25 Mbps, 34 Mbps, 43 Mbps, 100 Mbps or 155
Mbps) are used together with devices that are unable to perform or to signal speed
conversion.
A simple overall configuration variable MaxLineRate can be set to limit the total
peak-rate of the physical link between the uplink and the switch. This will affect all
VCs regardless of their individual traffic profile settings.
The traffic profile parameters are as follows:
Traffic Type
This value tells the switches involved in forwarding data traffic on a particular VCC
what type of traffic to expect.
Peak Rate (cells/sec)
This value specifies the maximum rate at which the VCC will transmit data.
Sustained Rate (cells/sec)
This value specifies the average rate at which the VCC will transmit data.
Maximum Burst Size (cells)
This value specifies the maximum number of cells sent at peak rate before
subsequent cells are sent at sustained rate.
Quality of Service
This value tells the switches involved in forwarding data traffic on a particular VCC
what QoS (or priority) the data traffic should be given.
The module hardware supports up to 63 concurrent traffic profiles. In addition to
this a “hardware default” traffic profile (full line rate) is defined.
Cell rates are approximated by the hardware, so the actual Peak/Sustained cell rates
used are as close to the specified values as permitted by the hardware.
Statistics programs may therefore show cell rates as being slightly different from
the rates specified in the configuration.