Brocade Converged Enhanced Ethernet Administrator's Guide v6.1.2_cee (53-1001258-01, June 2009)

118 Converged Enhanced Ethernet Administrator’s Guide
53-1001258-01
Converged Enhanced Ethernet
8
Converged Enhanced Ethernet
The CEE QoS covers packet classification, priority and traffic class (queue) mapping, congestion
control, and scheduling. Under the CEE Provisioning model all of these features are configured
utilizing two configuration tables, Priority Group Table and Priority Table.
CEE Priority Group Table defines each Priority Group ID (PGID) and its scheduling policy (Strict
Priority versus DWRR, DWRR weight, relative priority), and partially defines the congestion control
(PFC) configuration. There are 16 rows in the CEE Priority Group Table. Table 22 presents the
default CEE Priority Group Table configuration.
Strict Priority versus DWRR is derived directly from the PGID value. All PGID with prefix 15 receive
Strict Priority scheduling policy and all PGID in the range 0 through 7 receive DWRR scheduling
policy. Relative priority between Priority Group is exactly the ordering of entries listed in the table,
with PGID 15.0 being highest priority and PGID 7 being lowest priority. Congestion control
configuration is partially specified by toggling the PFC column On or Off. This provides only partial
configuration of congestion control because the set of priorities mapped to the Priority Group is not
known, which leads into the CEE Priority Table.
CEE Priority Table defines each CoS mapping to Priority Group, and completes PFC configuration.
There are 8 rows in the CEE Priority Table. Table 23 shows the default CEE Priority Table
configuration.
TABLE 22 Default CEE Priority Group Table configuration
PGID Bandwidth% PFC
15.0 — N
15.1 — N
15.2 — N
15.3 — N
15.4 — N
15.5 — N
15.6 — N
15.7 — N
00N
10N
20N
30N
40N
50N
60N
70N