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Intel® NetStructure™ 480T Routing Switch User Guide
Observing DiffServ Information
When a packet arrives at the switch on an ingress port, the switch
examines the first six of eight TOS bits. These bits are called the
code point.
The switch can assign the QoS profile used to subsequently transmit
the packet based on the code point. The QoS profile controls a
hardware queue used when transmitting the packet out of the
switch, and determines the forwarding characteristics of a particular
code point.
You can enable or disable the observance of DiffServ information.
By default it is disabled. To enable observance of DiffServ
information use the command:
enable diffserv examination ports [<portlist> |
all]
Changing DiffServ Code Point Assignments in the
QoS Profile
Because the code point uses six bits, it has 64 possible values (26 =
64). By default, the values are grouped and assigned to the default
QoS profiles listed in Table10.9.
Table 10.9: Default Code Point-to-QoS Profile Mapping
Code Point QoS Profile
0-7 Qp1
8-15 Qp2
16-23 Qp3
24-31 Qp4
32-39 Qp5
40-47 Qp6
48-55 Qp7
56-63 Qp8