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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
Policing Configuration for ciscosoftphone
Two rate limiters are associated with the interface on which the
ciscosoftphone
port-based automatic
QoS macro is executed. The two rate limiters ensure that all inbound traffic on a Cisco SoftPhone port
has the following characteristics:
1.
The rate of DCSP 46 is at or less than that of the expected SoftPhone application rate (G.722 – worst
case).
2.
The rate of DSCP 24 is at or less than the expected signaling rate.
3.
All other traffic is remarked to DSCP 0 (default traffic).
Action 3 is accomplished by the default QoS ACL. Any traffic that exceeds actions (1) or (2) is
policed-dscp back to zero (remarked back to DSCP 0 - BE).
DSCP 46 is policed at the rate of 320 kbps with a burst of 20 kb. DSCP 24 is policed at 32 kbps with a
burst of 8 kb. The burst and rate values are based on worst-case G.722 codec with a 256-kbps maximum
packet length of 256 bytes and minor signaling with a maximum packet length of 1000 bytes. Signaling
is transmitted with DSCP 24 and the bearer channel of the SoftPhone stream with DSCP 46.
Trust type—config
untrusted
Item
Value
Trust type—runtime
untrusted
Default CoS—config
0
Default CoS—runtime
0
Trust-device
none
Trust-ext
Untrusted
Cos-ext
0
QoS ACL attached to port
trust-dscp aggregate POLICE_SOFTPHONE-DSCP46-x-y any
dscp-field 46
1,
2
trust-dscp aggregate POLICE_SOFTPHONE-DSCP24-x-y any
dscp-field 24 *
QoS ACL name
ACL_IP-SOFTPHONES-x-y
3,
4
QoS policers
aggregate POLICE_SOFTPHONE-DSCP46-3-1 rate 320 burst 20
policed-dscp
aggregate POLICE_SOFTPHONE-DSCP24-3-1 rate 32 burst 8
policed-dscp
QoS policer names
POLICE_SOFTPHONE-DSCP46-x-y
POLICE_SOFTPHONE-DSCP24-x-y
1.
x = module number (interface on which the port-based automatic QoS macro is applied).
2.
y = port number (if a range is specified, use the first number in the range).
3.
Only the IP QoS ACLs are applied (not IPX).
4.
If the ACL_IP-SOFTPHONE-x-y name is already in use, the name ACL_IP-SOFTPHONE-x-y-z, where z is a value from 1 to 99,
will be tried sequentially. If all these names are taken, an error message displays. A similar action is taken with the policer name
(see the
“Out of Policer Names” section on page 53-24
).
Table 53-8
Port-Specific Settings for Voice (ciscosoftphone Keyword) (continued)