Reference Guide

Quality of Service (QoS) | 671
You can create a custom WRED profile or use on of the five pre-defined profiles.
Create WRED Profiles
To create a WRED profile:
1. Create a WRED profile using the command
wred from CONFIGURATION mode.
2. The command
wred places you in WRED mode. From this mode, specify minimum and maximum
threshold values using the command
threshold.
Apply a WRED profile to traffic
Once you create a WRED profile you must specify to which traffic FTOS should apply the profile.
FTOS assigns a color (also called drop precedence)—red, yellow, or green—to each packet based on it
DSCP value before queuing it. DSCP is a 6 bit field. Dell Force10 uses the first three bits of this field (DP)
to determine the drop precedence. DP values of 110 and 100 map to yellow, and all other values map to
green. If you do not configure FTOS to honor DSCP values on ingress (Honor DSCP values on ingress
packets on page 665) see all traffic defaults to green drop precedence.
Assign a WRED profile to either yellow or green traffic from QOS-POLICY-OUT mode using the
command
wred.
Table 33-7. Pre-defined WRED Profiles (E-Series)
Default Profile
Name
Minimum
Threshold
Maximum
Threshold
wred_drop 0 0
wred_ge_y 1024 2048
wred_ge_g 2048 4096
wred_teng_y 4096 8192
wred_teng_g 8192 16384
Table 33-8. Pre-defined WRED Profiles (S4810)
Default Profile
Name
Minimum
Threshold
Maximum
Threshold
Maximum
Drop Rate
wred_drop 0 0 100
wred_teng_y 467 4671 100
wred_teng_g 467 4671 50
wred_fortyg_y 467 4671 50
wred_fortyg_g 467 4671 25