Nokia 7705 - Page 38

QoS and QoS Policies
38
Quality of Service Guide
3HE 11014 AAAC TQZZA Edition: 01
In order for unshaped 4-priority SAPs to compete fairly for bandwidth with 16-priority
shaped and unshaped SAPs, a single, aggregate CIR for all the 4-priority SAPs can
be configured. This aggregate CIR is applied to all the 4-priority SAPs as a group,
not to individual SAPs. In addition, the aggregate CIR is configured differently for
access ingress and access egress traffic. On the 7705 SAR-8 and 7705 SAR-18,
access ingress is configured in the config>qos>fabric-profile context. On the
7705 SAR-M, 7705 SAR-H, 7705 SAR-Hc, 7705 SAR-A, 7705 SAR-Ax,
7705 SAR-W, and 7705 SAR-Wx, access ingress is configured in the
config>system>qos>access-ingress-aggregate-rate context. For all platforms,
access egress configuration uses the config>port>ethernet context.
For more information about access ingress scheduling and traffic arbitration from the
16-priority and 4-priority schedulers toward the fabric, see Access Ingress Per-SAP
Aggregate Shapers (Access Ingress H-QoS).
Figure 3 Access Ingress Scheduling for 4-Priority and 16-Priority SAPs
(with Per-SAP Aggregate Shapers)
CoS-8
CoS-1
CoS-7
CoS-8
CoS-1
CoS-7
4-priority Scheduled
Unshaped SAPs
16-priority Scheduled
Shaped or
Unshaped SAPs
Buffer Mgmt
via WRED
or Tail Drop
4-priority
Scheduling
16-priority
Scheduling
per
SAP
RR
Rate
Fabric
per
SAP
CIR
(see Note 1)
Note 1: Aggregate shaper (CIR) for all the 4-priority unshaped SAPs.
Per SAP,
Per FC
Queuing
Per SAP,
2nd Tier
Aggregate
Shapers
Priority
Schedulers
Access Ingress
Aggregate Shaper &
Scheduler
Classification
nc
h1
be
nc
h1
be
Ethernet
SAPs
23369
Exp
In-Prof
BE
In-Prof
CoS-8
In-Prof
CoS-1
In-Prof
CoS-8
Out-Prof
CoS-1
Out-Prof
Exp
Out-Prof
BE
Out-Prof
Strict
Priority
Strict
Priority
CIR, PIR
CIR, PIR