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Catalyst 6500 Series Switch Software Configuration Guide—Release 8.7
OL-8978-04
Chapter 53 Using Automatic QoS
Using the Automatic QoS Macro on the Switch
The port is set to untrusted for all port types to prevent ingress QoS scheduling. The global automatic
QoS macro configures the policed-dscp-map to make sure that DSCP 46 is marked down to DSCP 0 and
that DSCP 24 is marked down to DSCP 0. The global automatic QoS macro configures the default QoS
IP ACL that is used to remark all the other traffic to DSCP 0.
Limitations for ciscosoftphone
Because there is a limit on the total number of policers and QoS ACLs that are supported on the
Catalyst 6500 series switches, similar limitations are associated with the
ciscosoftphone
automatic QoS
macro. Up to 1023 aggregate policers are supported. Approximately 500 Cisco SoftPhone interfaces are
supported (less interfaces are supported when other QoS ACLs and security ACLs are configured).
With a large number of Cisco SoftPhone interfaces, both the bootup time and NVRAM space could be
affected. The bootup time increases with a large number of Cisco SoftPhone instances. It is possible to
run out of NVRAM space with a high number of Cisco SoftPhone instances. To avoid running out of
NVRAM space, you might need to use the text configuration mode. For more information, see the
“Out
of TCAM Space” section on page 53-23
.
Port-Specific Automatic QoS Settings
—
trust cos
Use the
trust cos
automatic QoS keyword for the ports that require a “trust all” solution. Use the
keyword only on the ports that connect other switches or known servers because the port trusts all
inbound traffic marking in Layer 2 (CoS). Trusted boundary is disabled, and no QoS policing is
configured on these types of ports.
Table 53-9
outlines the details of the configuration after executing the automatic QoS trust macro on a
port. See the
“Port-Specific Automatic QoS—trust cos” section on page 53-22
for configuration
examples.
Table 53-9
Port-Specific Settings for Trust (trust cos Keyword)
Item
Value
Interface type
Port-based
Policy source—config
Local
Policy source—runtime
Local (as per default)
Trust type—config
Trust-cos
Trust type—runtime
Trust-cos
Default CoS—config
0 (as per default)
Default CoS—runtime
0 (as per default)
Trust-device
None
QoS ACL attached to port
trust-cos any (if 1q4t/2q2t port, otherwise none)
QoS ACL name
ACL_IP-TRUSTCOS (if 1q4t/2q2t port, otherwise
none)
1,
2
1.
Only the IP QoS ACLs are applied (not IPX).
2.
If the ACL_IP- TRUSTCOS name is already in use, the name ACL_IP- TRUSTCOS
x
, where
x
is a value from 1 to 99, will
be tried sequentially. If all these names are taken, a syslog message is displayed
.
Trust-ext
Untrusted
Cos-ext
0