Filter
Top Products
Quality of Service (QoS): Managing Bandwidth More Effectively
Using QoS Classifiers To Configure Quality of Service for Outbound Traffic
Assigning an 802.1p Priority to IP Packets on the Basis of the
ToS Precedence Bits
If a device or application upstream of the switch sets the precedence bits in
the ToS byte of IP packets, you can use this feature to apply that setting for
prioritizing packets for outbound port queues. If the outbound packets are in
a tagged VLAN, this priority is carried as an 802.1p value to the adjacent
downstream devices.
IP Precedence Syntax: qos type-of-service ip-precedence
Causes the switch to automatically assign an
802.1p priority to all IP packets by computing
each packet’s 802.1p priority from the precedence
bits the packet carries. This priority determines
the packet’s queue in the outbound port to which
it is sent. If the packet leaves the switch in a
tagged VLAN, it carries the 802.1p priority with
it to the next downstream device. (ToS IP Prece-
dence Default: Disabled)
no qos type-of-service
Disables all ToS classifier operation, including
prioritization using the precedence bits.
show qos type-of-service
When ip-precedence is enabled (or if neither ToS
option is configured), shows the ToS configura-
tion status. If diff-services is enabled, lists code-
point data as described under
“Assigning a DSCP
Policy on the Basis of the DSCP in IP Packets
Received from Upstream Devices” on page 15-31.
With this option, prioritization of outbound packets relies on the IP-Prece-
dence bit setting that IP packets carry with them from upstream devices and
applications. To configure and verify this option:
Default ToS Configuration
Current ToS Configuration
Figure 15-11. Example of Enabling ToS IP-Precedence Prioritization
15-26