The 6-port Ethernet 10Gbps Adapter card and the 7705 SAR-X are third-generation (Gen-3) hardware components. All other Ethernet hardware components are second-generation (Gen-2) components. See Table: Ethernet Adapter Card, Module, and Platform Generations for a list of second-generation and third-generation Ethernet adapter cards, ports, and platforms.
The 7705 SAR supports mix-and-match traffic management (TM) across LAG members, where one member is a port on a Gen-3 adapter card or platform and the other member is a port on a Gen-2 adapter card or platform. Mix-and-match LAG does not apply to the 7705 SAR-X because it has only Gen-3 Ethernet ports.
For mix-and-match LAG TM scenarios, the 7705 SAR supports a generic QoS configuration, where the operator can configure all the settings available on each generation adapter card, but it is the card responsible for transporting traffic that determines which settings are applicable. That is, only the settings that apply to the active member port are used.
For example, configuring scheduling-mode applies to Gen-2 adapter card SAPs but does not apply to the Gen-3 adapter card SAPs because Gen-3 cards support only one scheduling mode (4-priority), which is its implicit (default) scheduler mode and is not configurable.
Because it cannot be known whether SAP traffic rides over a Gen-2 or a Gen-3 adapter card and whether both adapter cards support H-QoS (tier 2, per-SAP shapers), the operator can choose to configure per-SAP aggregate CIR and PIR shaper rates. When the active link is on a Gen-2- or Gen-3-based port, per-SAP aggregate CIR and PIR rates are both used to enforce shaper rates, except when the active link is on a Gen-3-based port and traffic is in the network egress direction. In this case, only the PIR portion of the per-SAP aggregate rate is used to enforce shaper rates.
In the following descriptions of LAG configuration, scheduler-mode, agg-rate, and cir-rate refer to SAP configuration, as shown below for an Epipe SAP. Similar commands exist for SAPs in other services as well as for egress traffic.
config>service>epipe>sap lag-id>ingress#
scheduler-mode {4-priority | 16-priority}
agg-rate-limit agg-rate [cir cir-rate]
The SAP identifier in the previous command has a lag-id (LAG SAP), not a port-id (regular SAP). A LAG SAP references two ports (one active and one standby), but only one port at a time carries traffic.
The agg-rate is a PIR rate.
For information on traffic management for Gen-3 adapter cards and platforms, refer to the ‟QoS for Gen-3 Adapter Cards and Platforms” section in the 7705 SAR Quality of Service Guide.
For mix-and-match LAG configurations, the following behaviors apply.
The configured aggregate rate on the LAG SAP is used to dictate the per-SAP aggregate rate on the active LAG port, regardless of which generation of adapter card is used (Gen-3 or Gen-2) or the configured scheduler mode. On a Gen-2 adapter card, the aggregate rate only applies when the port is in 16-priority scheduler mode. This behavior implies the following points.
The scheduler mode can be set to 16-priority or 4-priority. When servicing packets, the Gen-2-based datapath uses the configured scheduler mode (16-priority or 4-priority), while the Gen-3-based datapath always uses 4-priority scheduling.
When the traffic is transported over a Gen-3-based port (that is, the active link is on a Gen-3-based adapter card), the aggregate rate (agg-rate) is used to enforce a maximum shaper rate, as is the aggregate rate CIR (cir-rate).
When the active link is on a Gen-2-based adapter card, both aggregate rate CIR and PIR (cir-rate and agg-rate) are used. The aggregate rate (PIR) enforces the per-SAP bandwidth limit, and the CIR is used to identify in-profile and out-of-profile packets for aggregate scheduling purposes.
In addition, the following items describe mix-and-match LAG configuration behavior (that is, how the LAG SAP settings are applied or ignored depending on the active member port).
For a LAG SAP, scheduler-mode, agg-rate, and cir-rate are all configurable on a per-SAP basis, regardless of the LAG member port combination (that is, both Gen-2 ports, both Gen-3 ports, or a Gen-2-/Gen-3 port mix).
Scheduler-mode can be set to 4-priority or 16-priority, regardless of the LAG member port combination.
Agg-rate and cir-rate can be set whether scheduler-mode is set to 4-priority or 16-priority.
The configured scheduler-mode applies to Gen-2-based LAG member ports only and is not used for Gen-3-based LAG member ports. Gen-3 cards always use 4-priority scheduler mode. The unshaped-sap-cir keyword does not apply to Gen-3 SAPs because Gen-3 SAPs are all shaped SAPs.
If scheduler-mode is 4-priority on the LAG SAP, where the LAG has one Gen-2-based port member and one Gen-3-based port member, the following points apply.
The Gen-2-based adapter card is configured with 4-priority scheduling, while agg-rate and cir-rate are not applied, and H-QoS is not enabled.
The Gen-3-based adapter card is configured with agg-rate and cir-rate, while scheduler-mode is ignored.
When LAG active/standby switching occurs from an active Gen-3-based port to an active Gen-2-based port, traffic management is changed from a 4-priority scheduler with H-QoS to a 4-priority scheduler without H-QoS that functions like an unshaped SAP.
For the reverse case, when LAG active/standby switching occurs from an active Gen-2-based port to an active Gen-3-based port, traffic management is changed from a 4-priority scheduler without H-QoS to a 4-priority scheduler with H-QoS.
If scheduler-mode is 16-priority on the LAG SAP, where the LAG has one Gen-2-based port member and one Gen-3-based port member, the following points apply.
The Gen-2-based adapter card is configured with 16-priority scheduling mode, agg-rate and cir-rate. This means that H-QoS is enabled.
The Gen-3-based adapter card is configured with agg-rate and cir-rate, while scheduler-mode is ignored.
When LAG active/standby switching occurs from an active Gen-3-based port to an active Gen-2-based port, traffic management is changed from a 4-priority scheduler with H-QoS using the agg-rate and cir-rate, to a 16-priority scheduler with H-QoS using the agg-rate and the cir-rate (that is, from 4-priority (Gen-3) mode to 16-priority mode for shaped SAPs).
For the reverse case, when LAG active/standby switching occurs from an active Gen-2-based port to an active Gen-3-based port, traffic management is changed from a 16-priority scheduler with H-QoS using the agg-rate and the cir-rate, to a 4-priority (Gen-3) scheduler with H-QoS enabled using the agg-rate and the cir-rate.
If scheduler-mode is 16-priority mode on the LAG SAP, the combination of a Gen-1-based port with a Gen-2-based or Gen-3-based port is blocked because Gen-1 adapter cards do not support 16-priority mode. The only valid option for this combination of ports is 4-priority scheduling mode.
Lastly, for LAG on access ports, the primary port configuration settings are applied to both the primary and secondary LAG ports. Therefore, in order to support unshaped SAPs when the primary port is a Gen-3-based port and the secondary port is a Gen-2-based port, configuring the unshaped-sap-cir on the Gen-3-based port is allowed, even though it does not apply to the Gen-3-based port. This is because unshaped-sap-cir is needed by the secondary Gen-2-based port when it becomes the active port. The full command is config>port>ethernet>access>egress> unshaped-sap-cir cir-rate.