5-16
Quality of Service: Managing Bandwidth More Effectively
Globally-Configured QoS
Globally-Configured QoS
Note For more information on how to use global QoS classifiers, see “Global QoS
Restrictions” on page 5-19.
Global QoS Configuration Procedure
To globally configure a QoS policy on the switch, follow these steps:
1. Determine the global QoS policy you want to implement on the switch by
analyzing the types of traffic flowing through your network and identify-
ing one or more traffic types to prioritize. The order of precedence, from
a (highest) to h (lowest), in which global QoS classifiers are applied is as
follows:
a. TCP/UDP applications
b. Device priority—IP source or destination address (Note that destina-
tion has precedence over source. See Table 5-5.)
c. IP precedence bit set (leftmost three bits in the ToS/Traffic Class field
of IP packets)
d. IP differentiated services bit set (leftmost six bits in the ToS/Traffic
Class field of IP packets)
e. Layer-3 protocol
f. VLAN ID (requires at least one tagged VLAN on the network)
g. Source port
h. Incoming 802.1p priority (requires at least one tagged VLAN on the
network)
QoS Feature Default Reference
UDP/TCP Priority Disabled page 5-21
IP-Device Priority Disabled page 5-32
IP Type-of-Service Priority Disabled page 5-40
Layer-3 Protocol Priority Disabled page 5-53
VLAN-ID Priority Disabled page 5-55
Source-Port Priority Disabled page 5-62