Specifications

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Cisco MWR 2941 Mobile Wireless Edge Router Software Configuration Guide, Release 12.2(33)MRB
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Appendix B Cisco MWR 2941 Router Command Reference
random-detect dscp
Usage Guidelines Use the random-detect dscp command in conjunction with the random-detect command in interface
configuration mode.
Additionally, the random-detect dscp command is available only if you specified the dscp-based
argument when using the random-detect command in interface configuration mode.
Note The random-detect dscp command is not available at the interface level for Cisco IOS Release 12.1E
or Release 12.0S. The random-detect dscp command is available only in policy-map class
configuration mode in Cisco IOS Release 12.1E.
Specifying the DSCP Value
The random-detect dscp command allows you to specify the DSCP value per traffic class. The DSCP
value can be a number from 0 to 63, or it can be one of the following keywords: af11, af12, af13, af21,
af22, af23, af31, af32, af33, af41, af42, af43, cs1, cs2, cs3, cs4, cs5, cs7, ef, or rsvp.
On a particular traffic class, eight DSCP values can be configured per traffic class. Overall, 29 values
can be configured on a traffic class: 8 precedence values, 12 AF code points, 1 EF code point, and 8
user-defined DSCP values.
Assured Forwarding Code Points
The AF code points provide a means for a domain to offer four different levels (four different AF
classes). Forwarding assurances for IP packets received from other (such as customer) domains. Each
one of the four AF classes is allocated a certain amount of forwarding services (buffer space and
bandwidth).
Within each AF class, IP packets are marked with one of three possible drop precedence values (binary
2{010}, 4{100}, or 6{110}), which exist as the three lowest bits in the DSCP header. In congested
network environments, the drop precedence value of the packet determines the importance of the packet
within the AF class. Packets with higher drop precedence values are discarded before packets with lower
drop precedence values.
The upper three bits of the DSCP value determine the AF class; the lower three values determine the
drop probability.
Expedited Forwarding Code Points
The EF code point is usually used to mark high-priority, time-sensitive data. The EF code point marking
is equal to the highest precedence value; therefore, the EF code point is always equal to precedence value
7.
12.2(14)S This command was integrated into Cisco IOS Release 12.2(14)S.
12.2(28)SB This command was integrated into Cisco IOS Release 12.2(28)SB.
12.2(33)SRA This command was integrated into Cisco IOS Release 12.2(33)SRA.
12.2SX This command is supported in the Cisco IOS Release 12.2SX train. Support
in a specific 12.2SX release of this train depends on your feature set,
platform, and platform hardware.
12.4(20)MR This command was integrated into Cisco IOS Release 12.4(20)MR.
12.2(33)MRA This command was integrated into Cisco IOS Release 12.2(33)MRA.
Release Modification