Quality of Service Guide QoS and QoS Policies
Edition: 01 3HE 11014 AAAC TQZZA 157
3.7.8 ATM Traffic Descriptor Profiles
Traffic descriptor profiles capture the cell arrival pattern for resource allocation.
Source traffic descriptors for an ATM connection include at least one of the following:
• Sustained Information Rate (SIR)
• Peak Information Rate (PIR)
• Minimum Information Rate (MIR)
• Maximum Burst Size (MBS)
QoS traffic descriptor profiles are applied on ATM VLL (Apipe) SAPs.
3.7.9 Fabric Profiles
Fabric profiles allow access and network ingress to-fabric shapers to have
user-configurable rates of switching throughput from an adapter card towards the
fabric.
Two fabric profile modes are supported: per-destination mode and aggregate mode.
Both modes offer shaping towards the fabric from an adapter card, but
per-destination shapers offer the maximum flexibility by precisely controlling the
amount of traffic to each destination card at a user-defined rate.
For the 7705 SAR-8 and the 7705 SAR-18, the maximum rate depends on a number
of factors, including platform, chassis variant, and slot type. See Configurable
Ingress Shaping to Fabric (Access and Network) for details. For information about
fabric shaping on the 7705 SAR-M, 7705 SAR-H, 7705 SAR-Hc, 7705 SAR-A,
7705 SAR-Ax, 7705 SAR-W, and 7705 SAR-Wx, see Fabric Shaping on the Fixed
Platforms (Access and Network).
Note:
• If an adapter card or platform other than a third-generation adapter card or platform is
used in the previous example (that is, an adapter card or platform with buffer-based
WRED), both WRED and tail drop start after 100 buffers are consumed, because both
128-byte and 512-byte frames fill one buffer (512 bytes).
• Since tail drop (which is buffer-based) and WRED (which is payload-based) operate
differently, it is not recommended that tail drop and WRED be used in the same queue.
To Next Page
Loading...
