Extreme Networks ExtremeWare XOS 10.1, Руководство пользователя

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Traffic Groupings
ExtremeWare XOS 10.1 Concepts Guide 87
Observing 802.1p Information
When ingress traffic that contains 802.1p prioritization information is detected by the switch, the traffic
is mapped to various hardware queues on the egress port of the switch. Eight hardware queues are
supported. The transmitting hardware queue determines the bandwidth management and priority
characteristics used when transmitting packets.
To control the mapping of 802.1p prioritization values to hardware queues, 802.1p prioritization values
can be mapped to a QoS profile. The default mapping of each 802.1p priority value to QoS profile is
shown in Table 14.
Changing the Default 802.1p Mapping
By default, a QoS profile is mapped to a hardware queue, and each QoS profile has configurable
bandwidth parameters and priority. In this way, an 802.1p priority value seen on ingress can be mapped
to a particular QoS profile and with specific bandwidth management and priority behavior.
To change the default mappings of QoS profiles to 802.1p priority values, use the following command:
configure dot1p type <dot1p_priority> qosprofile <qosprofile>
Configuring DiffServ
Contained in the header of every IP packet is a field for IP Type of Service (TOS), now also called the
DiffServ field. The TOS field is used by the switch to determine the type of service provided to the
packet.
Observing DiffServ code points as a traffic grouping mechanism for defining QoS policies and
overwriting the Diffserv code point fields are supported.
Figure 8 shows the encapsulation of an IP packet header.
Table 14: 802.1p Priority Value-to-QoS Profile Default Mapping
Priority Value QoS Profile
0 Qp1
1 Qp2
2 Qp3
3 Qp4
4 Qp5
5 Qp6
6 Qp7
7 Qp8