Understanding Cos Code-Point Aliases; Default Code-Point Aliases - Juniper JUNOS OS 10.4 - FOR EX REV 1 Manual

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Understanding CoS Code-Point Aliases

Default Code-Point Aliases

3378
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OS for EX Series Ethernet Switches, Release 10.4
Understanding CoS Code-Point Aliases on page 3378
Understanding CoS Classifiers on page 3381
Understanding CoS Forwarding Classes on page 3384
Understanding CoS Tail Drop Profiles on page 3386
Understanding CoS Schedulers on page 3387
Understanding CoS Two-Color Marking on page 3390
Understanding CoS Rewrite Rules on page 3390
Example: Configuring CoS on EX Series Switches on page 3401
A code-point alias assigns a name to a pattern of code-point bits. You can use this name
instead of the bit pattern when you configure other CoS components such as classifiers,
drop-profile maps, and rewrite rules.
Behavior aggregate classifiers use class-of-service (CoS) values such as Differentiated
Services code points (DSCPs), IP precedence, and IEEE 802.1 bits to associate incoming
packets with a particular CoS servicing level. On a switch, you can assign a meaningful
name or alias to the CoS values and use this alias instead of bits when configuring CoS
components. These aliases are not part of the specifications but are well known through
usage. For example, the alias for DSCP 101110 is widely accepted as ef (expedited
forwarding).
When you configure classes and define classifiers, you can refer to the markers by alias
names. You can configure user-defined classifiers in terms of alias names. If the value
of an alias changes, it alters the behavior of any classifier that references it.
You can configure code-point aliases for the following type of CoS markers :
dscp—Handles incoming IPv4 packets.
ieee-802.1—Handles Layer 2 CoS.
inet-precedence—Handles incoming IPv4 packets. IP precedence mapping requires
only the upper three bits of the DSCP field.
This topic covers:
Default Code-Point Aliases on page 3378
Table 439 on page 3379 shows the default mappings between the bit values and standard
aliases.
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