Cisco 15327 - Manual (Page 235)

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Ethernet Card Software Feature and Configuration Guide, R7.2
Chapter 14 Configuring Quality of Service
QoS not Configured on Egress
QoS not Configured on Egress
The QoS bandwidth allocation of multicast and broadcast traffic is handled separately from unicast
traffic. On each interface, the aggregate multicast and broadcast traffic are given a fixed bandwidth
commit of 10% of the interface bandwidth. This is the optimum bandwidth that can be provided for
traffic exceeding 10% of the interface bandwidth.
Figure 14-10 QoS not Configured on Egress
ML-Series Egress Bandwidth Example
This section explains with examples the utilization of bandwidth across different queues with or without
Priority Multicast.
Case 1: QoS with Priority and Bandwidth Configured Without Priority Multicast
Strict Priority Queue is always serviced first. The remaining interface bandwidth is utilized to service
other configured traffic.
In the following example, after servicing unicast customer_voice traffic, the remaining interface
bandwidth is utilized for other WRR queues such as customer_core_traffic , customer_data, and
class-default
in the ratio of 1:3:5.
At any given time, the sum of the bandwidth assigned cannot exceed the interface bandwidth (in kbps).
The bandwidth share allocated to
class-default will be utilized by default unicast traffic (in this
example, unicast traffic with CoS values other than 2, 5, 7) and all multicast/broadcast traffic (all CoS
values). The default unicast and all multicast/broadcast traffic will be serviced in the ratio of 9:1.
Traffic at Egress
without QoS
Multicast/Broadcast
service up to 90%
interface BW and
best effort service
for exceeding traffic
Guaranteed
Service
Best Effort
Service
False
True
False
True
Unicast Traffic?
If rate < 10%
interface BW
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