DGS-3024 Layer 2 Switch CLI Reference Manual
The QoS commands in the Command Line Interface (CLI) are listed (along with the appropriate parameters) in the following
table.
Command Parameters
config scheduling
<class_id 0-3> max_packet <value 0-15>
show scheduling
config 802.1p user_priority
<priority 0-7> <class_id 0-3>
show 802.1p user_priority
config 802.1p default_priority
[<portlist> | all] <priority 0-7>
show 802.1p default_priority
{<portlist>}
Each command is listed, in detail, in the following sections.
config scheduling
Purpose
Used to configure traffic scheduling for each of the Switch’s QoS
queues.
Syntax
config scheduling <class_id 0-3> {max_packet <value 0-15}
Description
The Switch contains four hardware priority classes of service per
device. The Switch’s default settings draw down the four hardware
classes of service in order, from the highest class (Class 3) to the
lowest class (Class 0). Starting with the highest priority class of
service (Class 3), the highest priority class of service will transmit all
of the packets and empty its buffer before allowing the next lower
priority class of service to transmit its packets. The next highest
priority class of service will empty before proceeding to the next
class of service and so on. Lower priority classes of service are
allowed to transmit only if the higher priority classes of service in the
buffer are completely emptied. Packets in the higher priority classes
of service are always emptied before any in the lower priority
classes of service regardless of latency or volume of the lower
priority classes of service.
The default settings for QoS scheduling employ this strict priority
scheme to empty priority classes of service.
The
config scheduling
command can be used to specify the round
robin rotation by which these four hardware priority classes of
service are reduced. To use a round-robin scheme, the
max_packet
parameter must be changed from the default value of 0.
The
max_packet
parameter allows you to specify the maximum
number of packets a given priority classes of service can transmit
before allowing the next lowest priority queue to begin transmitting
its packets. A value between 0 and 15 packets can be specified. For
example, if a value of 5 is specified, then the highest priority class of
service (queue 3) will be allowed to transmit 5 packets. Then the
next lower priority class of service (queue 2) will be allowed to
transmit 5 packets, and so on, until all of the classes of service have
transmitted 5 packets. The process will then repeat.
Parameters
<class_id>
−
Specifies which of the four priority classes of service to
which the
config scheduling
command will be applied. The four
priority classes of service are identified by number
−
from 0 to 3
−
with class 3 being the highest priority.
max_packet <value 0-15>
−
Specifies the maximum number of
packets the above specified priority class of service will be allowed
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