Quality of Service Guide QoS and QoS Policies
Edition: 01 3HE 11014 AAAC TQZZA 97
Note:
1. 4-priority scheduler for Gen-3 adapter card or platform.
3.4.3.1 Network Egress 4-Priority Scheduling
The implementation of network egress scheduling on the cards and ports listed in
Table 10 under “4-Priority” is very similar to the scheduling mechanisms used for
adapter cards that are configured for access ingress traffic. 4-priority scheduling is a
combination of queue-type scheduling (Expedited vs. Best-effort scheduling) and
profiled scheduling (rate-based scheduling).
Packets less than or up to the CIR are scheduled as in-profile. Packets that arrive at
rates greater than the CIR, but less than the PIR, are scheduled as out-of-profile.
In-profile traffic is exhaustively transmitted from the queues before out-of-profile
traffic is transmitted. That is, all of the in-profile packets must be transmitted before
any out-of-profile packets are transmitted. In addition, Expedited queues are always
scheduled prior to Best Effort queues.
The default configuration of scheduling CoS queues provides a logical and
consistent means to manage the traffic priorities. The default configuration is as
follows:
• CoS-8 to CoS-5 Expedited in-profile
• CoS-4 to CoS-1 Best Effort in-profile
• CoS-8 to CoS-5 Expedited out-of-profile
• CoS-4 to CoS-1 Best Effort out-of-profile
Note: The encapsulation type must be ppp-auto for PPP/MLPPP bundles on the following:
• T1/E1 ports on the 7705 SAR-A (variants with T1/E1 ports)
• T1/E1 ports on the 7705 SAR-M (variants with T1/E1 ports)
• T1/E1 ports on the 7705 SAR-X
• 16-port T1/E1 ASAP Adapter card
• 32-port T1/E1 ASAP Adapter card
• 2-port OC3/STM1 Channelized Adapter card
• 4-port OC3/STM1 / 1-port OC12/STM4 Adapter card
• T1/E1 ports on the 4-port T1/E1 and RS-232 Combination module (on 7705 SAR-H)
Note: Default configuration means that the queues are configured according to the tables
and defaults described in this guide. Customers can configure the queues differently.
To Next Page
Loading...
