128
Link Scheduler Configuration
Tagged Frame Type Interpretation
Always set to 8100h for Ethernet frames (802.3ac tag
format)
3-Bit Priority Field (802.1p)
Value from 0 to 7 representing user priority levels (7 is the
highest)
Canonical
Always set to 0
12-Bit 802.1Q VLAN Identifier
VLAN identification number
Table
raffic Control Info (TCI) Field
802.1p-compliant infrastructure devices read the 3-bit user priority field and route the frame through
an internal buffer/queue mapped to the corresponding user priority level.
The command
set layer2 cos
specifies the layer 2 marking applied to packets of this class by setting
the 3-bit priority field (802.1p). The
no
form of this command disables packet marking.
Procedure
Defining the 3-bit priority field (802.1p)
Mode
Source
Command Purpose
15-4: T
node
(src)[
name
]#set layer2 cos
value
Defines the Class-Of-Service value applied to
packets of for the
selected class or policy
name
.
The range for
value
is from 0 to 7.
15.8.9 Defining Random Early Detection
The command
random-detect
is used random early detection (RED) for queues that carry lots of TCP
transfers that last longer than simple web requests. In such a case there is a risk that TCP flow-
control might be ineffective. With RED configured the queue occasionally drops packets when the
queue has grown over half the “queue-limit”. This improves the performance of TCP flow-control. A
burst-tolerance index between 1 and 10 may optionally be specified (exponential filter weight). The
no
form of this command reverts the queue to default “tail-drop” behavior.
Procedure
Defining random early detection
Mode
Source
Command Purpose
node
(src)[
name
]#random-detect
{
burst-tolerance
} Defines random early detection (RED) for
queues of for the
selected class or policy
name.
The
range for the optional
value
burst-tolerance
is from 1 to 10.
15.8.10 Discarding Excess Load
The command
police
controls traffic arriving in a queue for class
name
. The value of the first
argument
average-kilobits
defines the average permitted rate in kBits/s, the value of the second
Software Configuration Guide, Revision 1.03