Qos Settings - GE T1000 Technical Manual

GE Reason Switches
11

QoS Settings

11.1 Port Classification
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Quality of service function is used to guarantee performance of a determined traffic
when network at the LAN (or VLAN) is congested. It can be performed in many
communication layers. Reason Switches can perform QoS function at the CoS and
DSCP bits, that is, layer 2 and layer 3 communication. In addition, QoS functions are
also used to prevent storms and congestion at the networks.
CoS bits are the priority bits embedded at the 802.1Q frames, that is, VLAN-tagged
frames will carry information of class-of-service to be used by the frame. Untagged
frames will be classified as the switch is configured to do. CoS-based QoS
configuration allowed are shown in the Port Classification, Port Policing, Queue
Policing, Port Scheduler, Port Shaping and Port Tag Remarking menus.
DSCP bits are the priority bits embedded at IP packet. IP communication can carry
class-of-service information on these bits. The DSCP-based QoS configurations
allowed are shown in the Port DSCP, DSCP-based QoS, DSCP Translation, DSCP
Classification, and QoS Control List menus.
Storm prevention functions are shown in the Port Policing and WRED menus.
QoS menu is located at Settings
Port Classification menu allows configuring basic QoS ingress classification at a given
port.
If one configuration is desired to be applied at all ports, then the row "*" should be
used, that is, configuration done in the "*" row will be replied to all ports. Possible
configurations are as follows
Port: shows the ports to be configured at this row;
o
CoS: indicates CoS that will be used the ingress process. These
o
ports will classify untagged frames to the CoS class configured at
this field and will forward tagged and priority-tagged frames to the
CoS queue embedded at the PCP bits in the 802.1Q frame. By
default, all untagged frames are classified to the CoS 0 queue,
which means lowest priority class-of-service for that packets. Also,
by default there is a one-to-one mapping of CoS and PCP bits.
Allowed values are the PCP bits range values (from 0 to 7);
DPL: indicates the Drop Precedence Level to be used in the ingress
o
process. These ports will classify untagged frames to the DPL class
configured at this field and will forward tagged and priority-tagged
frames to the DPL embedded at the frame. DPL level 0 means that
packet cannot be dropped, and level 1, 2 and 3 means that packet
can be dropped randomly based on the WRED threshold. By

QoS.
REASON SWITCHES-TM-EN-3
Chapter 7 – Configuration