Quality of Service Guide QoS and QoS Policies
Edition: 01 3HE 11014 AAAC TQZZA 77
Note:
1. 4-priority scheduler for Gen-3 adapter card or platform.
3.2.3.1 Profiled (Rate-based) Scheduling
Each queue is serviced based on the user-configured CIR and PIR values. If the
packets that are collected by a scheduler from a queue are flowing at a rate that is
less than or equal to the CIR value, then the packets are scheduled as in-profile.
Packets with a flow rate that exceeds the CIR value but is less than the PIR value
are scheduled as out-of-profile. Figure 16 depicts this behavior by the “In-Prof” and
“Out-Prof” labels. This behavior is comparable to the dual leaky bucket
implementation in ATM networks. With in-profile and out-of-profile scheduling, traffic
that flows at rates up to the traffic contract (that is, CIR) from all the queues is
serviced prior to traffic that flows at rates exceeding the traffic contract. This mode of
operation ensures that Service Level Agreements are honored and traffic that is
committed to be transported is switched prior to traffic that exceeds the contract
agreement.
3.2.3.2 Queue-Type Scheduling
As well as profiled scheduling described above, queue-type scheduling is supported
at access ingress. Queues are divided into two categories, those that are serviced
by the Expedited scheduler and those that are serviced by the Best Effort scheduler.
6-port FXS Adapter card ✓
8-port FXO Adapter card ✓
8-port Voice & Teleprotection card ✓
Integrated Services card ✓
Table 8 Scheduling Modes Supported by Adapter Cards and Ports at
Access Ingress (Continued)
Adapter Card or Port 4-Priority 16-Priority
Note: A profile is an arithmetical analysis of the rates that are permitted for a particular
packet flow; therefore, profiled scheduling may also be called rate-based scheduling.
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