156
XS712T Smart Switch
2. To configure CoS settings for a specific interface, enter the interface and click Go to select
that particular interface.
3. Alternatively, select the check box associated with each interface for which you want to
configure the CoS settings:
•To configure CoS settings for a Link Aggregation Group (LAG), click LAGS.
•To configure CoS settings for both physical ports and LAGs, click ALL.
The same settings will be applied to all selected interfaces.
4. From the Interface Trust Mode drop down list, select the trust mode for ingress traffic on the
selected interfaces.
•Untrusted. Do not trust any CoS packet marking at ingress.
•802.1p. The eight priority tags that are specified in IEEE 802.1p are p0 to p7. The
QoS setting lets you map each of the eight priority levels to one of seven internal
hardware priority queues.
•DSCP. The six most significant bits of the DiffServ field are called the Differentiated
Services Code Point (DSCP) bits.
5. In the Interface Shaping Rate field, specify the maximum bandwidth allowed.
This is typically used to shape the outbound transmission rate in increments of 64 kbps in
this range of 16–16384. This value is controlled independently of any per-queue
maximum bandwidth configuration. It is effectively a second-level shaping mechanism.
The default value is 0. The value 0 means maximum is unlimited.
The expected shaping at egress interface is calculated as:
frameSize*shaping/(frameSize+IFG), where IFG (Inter frame gap) is 20 bytes, frameSize
is configured frame size of the traffic and shaping is configured traffic shaping in the
Interface Shaping Rate field.
For example, when the frame size is 64 bytes and the interface shaping rate is 64, the,
expected shaping will be approximately 48kbps.
Setting the value to 0 resets the configured traffic-shape rate.
6. Click Apply.
Interface Queue Configuration
Use the Interface Queue Configuration screen to define what a particular queue does by
configuring switch egress queues. User-configurable parameters control the amount of
bandwidth used by the queue, the queue depth during times of congestion, and the
scheduling of packet transmission from the set of all queues on a port. Each port has its own
CoS queue-related configuration.
The configuration process is simplified by allowing each CoS queue parameter to be
configured globally or per-port. A global configuration change is automatically applied to all
ports in the system.