HP Networking TopTool Products manual Configuring a QoS Policy for IP Type Service ToS, 11-6

Quality of Service

Configuring a QoS Policy for IP Type of Service (ToS)

7.Click on OK. This returns you to the IP Device Address page. Repeat steps 4 through 7 for up to 30 IP Address policies.

Click on the Apply All IP Address Policies button. All buttons will appear temporarily grayed-out. When the Add New Policy button re-activates, any new IP address policies you entered have been configured on the QoS-enabled switches that HP TopTools has discovered in your network.

Configuring a QoS Policy for IP Type of

Service (ToS)

Every IP packet includes a ToS field. This field carries priority settings that are read and used, but not altered by HP Procurve switches. When an HP TopTools prioritization policy is configured for ToS criteria, the Procurve switches in the network read the content of the ToS field in packets received from upstream devices and applications and take actions based on whether the policy applies to the packets. To use ToS to configure priority, you need to anticipate the ToS field settings in IP packets entering Procurve switches from upstream devices. This involves having knowledge of how an upstream device or application will set the bits in the ToS field of IP packets transmitted onto the network. A ToS policy can prioritize IP packets in either of two ways:

■Use the Differentiated Services bits to select the packets to prioritize (ToS Differentiated Services option)

■Use the Precedence bits to prioritize a packet (ToS IP precedence option)

ToS Configuration Options

ToS policy configuration includes three options:

■Disabled (the default) -- ToS is disabled and is not a factor in prioritizing packets. (Priority settings in the ToS fields of IP packets are ignored by the HP Procurve switches in the network.)

■IP Precedence -- ToS is enabled, and Procurve switches will use ToS precedence bits (the upper three bits in the ToS field of packets received from upstream devices) to determine packet priority. The value of these bits is in the range of 0 through 7.

■Differential Services -- ToS is enabled and Procurve switches will use the Differentiated Services bits (the upper six bits of the ToS field). Each possible setting is termed a codepoint, and there are 64 possible code- points. This means that you can configure a priority (0 - 7) for up to 64 ToS codepoints. If No override (the default) is specified for a codepoint, then differentiated services prioritization is not used for packets carrying that codepoint. Using HP TopTools for Hubs & Switches, you can enable or disable the Differentiated Services option. To configure the priority policy corresponding to the codepoints in the ToS fields for IP packets, telnet to the console interface of the individual Procurve switches in your

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