SMC Networks SMC6824M manual 209, Mapping IP Precedence

CLASS OF SERVICE CONFIGURATION

•IP Precedence – Maps layer 3/4 priorities using IP Precedence.

•IP DSCP – Maps layer 3/4 priorities using Differentiated Services Code Point Mapping.

Web – Click Priority, IP Precedence/DSCP Priority Status. Select Disabled, IP Precedence or IP DSCP from the scroll-down menu, then click Apply.

Figure 3-92 Setting IP Precedence/DSCP Priority Status

CLI – The following example enables IP Precedence service on the switch.

Console(config)#map ip precedence	4-262
Console(config)#

Mapping IP Precedence

The Type of Service (ToS) octet in the IPv4 header includes three precedence bits defining eight different priority levels ranging from highest priority for network control packets to lowest priority for routine traffic. The default IP Precedence values are mapped one-to-one to Class of Service values (i.e., Precedence value 0 maps to CoS value 0, and so forth). Bits 6 and 7 are used for network control, and the other bits for various application types. ToS bits are defined in the following table.

Table 3-14 Mapping IP Precedence

Priority Level	Traffic Type	Priority Level	Traffic Type
7	Network Control	3	Flash
6	Internetwork Control	2	Immediate
5	Critical	1	Priority
4	Flash Override	0	Routine

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