Using HP-UX VLANs (September 2004)

Overview of Installation and Configuration
How is 802.1p Priority Set?
Chapter 2 37
How is 802.1p Priority Set?
IP packets are classified and marked into different priority levels and the
markings are transported through a type of service (ToS) octet in the
IPv4 header and a traffic class field in the IPv6 header.
HP-UX end stations transmit IPv4 type-of-service (ToS) values but do
not enforce priority. The end stations perform ToS-to-802.1p conversion
and vice-versa for IP packets depending on how the VLAN overrides are
set. They also allow 802.1p priority setting for non-IP packets.
Priority may be set by user, destination address, input port, output port,
access priority, or by VLAN. User priority is a 3-bit field which allows
priority information to be encoded in the frame. The eight levels of IEEE
802.1p recommended user priorities are shown in Table 2-3.
Table 2-3 ToS to 802.1 User Priority Mappings Based on IP Precedence
HP WebQoS ToS
Value Range
IEEE 802.1p
User
Priority
Traffic Type
0xE0 - 0xFF 7 (highest) Network Management
0xC0 - 0xDF 6 Voice
0xA0 - 0xBF 5 Video
0x80 - 0x9F 4 Controlled Load
0x60 - 0x7F 3 Excellent Effort
0x40 - 0x5F 0 (routine
traffic)
Best Effort
0x20 - 0x3F 2 Undefined
0x00 - 0x1F 1 (lowest) Background