adaptation-rule [pir adaptation-rule] [cir adaptation-rule]
no adaptation-rule
config>qos>sap-ingress>queue
config>qos>sap-egress>queue
This command can be used to define how an operational rate is selected based on the configured PIR or CIR rate. Operational rates are the finite set of rates at which the schedulers on the network processor can operate.
The no form of the command removes any adaptation-rule constraints used to derive the operational rates for the policy. When a specific adaptation-rule is removed, the default constraints for rate and cir apply.
pir closest cir closest
pir defines the constraints enforced when adapting the PIR rate defined within the queue queue-id rate command. The pir keyword requires a qualifier that defines the constraint used when deriving the operational PIR rate for the queue. When the rate command is not specified, the default applies.
cir defines the constraints enforced when adapting the CIR rate defined within the queue queue-id rate command. The cir keyword requires a qualifier that defines the constraint used when deriving the operational CIR rate for the queue. When the cir keyword is not specified, the default constraint applies.
specifies the constraints to be used while computing the operational CIR or PIR rate. The max (maximum), min (minimum), and closest parameters are mutually exclusive.
cbs {size-in-kbytes | default}
no cbs
config>qos>sap-ingress>queue
config>qos>sap-egress>queue
This command overrides the default Committed Buffer Space (CBS) reserved for buffers of a specified queue. The value is configured in kilobytes.
The value in kilobytes is converted automatically to the number of buffers. The conversion calculation uses a non-configurable buffer size of 2304 bytes or 512 bytes, depending on the type of adapter card. See Table: Buffer Support on Adapter Cards and Platforms for a list of adapter cards and their associated buffers. The calculation is:
Number of buffers = Configured CBS value in bytes / Buffer size in bytes
At the egress of an N > 1 Apipe, the CBS value in a SAP egress QoS policy that is assigned to a SAP aggregation group causes n times that value of buffers to be committed, where n is the number of SAPs in the SAP aggregation group. See the show pools command for information about how to view buffer pools for SAPs that are members of a SAP aggregation group. See the 7705 SAR Services Guide for information about how to configure SAP aggregation groups.
The no form of this command returns the CBS size to the default value.
‟default” (8 kbytes for adapter cards and platforms with 512 byte buffer size) (18 kbytes for adapter cards and platforms with 2304 byte buffer size).
this parameter is an integer expression of the number of kilobytes reserved for the queue. A value of 0 specifies that no reserved buffers are required by the queue (a minimal reserved size can still be applied for scheduling purposes).
returns the CBS size to the default value
high-prio-only percent
no high-prio-only
config>qos>sap-ingress>queue
config>qos>sap-egress>queue
This command configures the percentage of buffer space for the queue, used exclusively by high-priority packets. The specified value overrides the default value for the context.
The priority of a packet can only be set in the service ingress policy and is only applicable on the ingress queues for a SAP. The profile state is used for enqueuing priority at sap-egress.
The no form of this command restores the default high-priority reserved size.
the percentage reserved for high priority traffic on the queue
mbs size [bytes | kilobytes]
no mbs
config>qos>sap-ingress>queue
config>qos>sap-egress>queue
This command sets the Maximum Burst Size (MBS) value for the buffers of the specified queue. The value is configured in bytes or kilobytes, and overrides the default MBS value. The default configuration is in kilobytes.
The config>qos>sap-ingress>info detail and sap-egress>info detail screens show the MBS in terms of bytes, unless it is a multiple of 1000. In that case, the display shows the MBS in kilobytes. For example, entering mbs 200 or mbs 200 kilobytes configures and displays ‟200 kilobytes”, entering mbs 200000 bytes also configures and displays ‟200 kilobytes”, and entering mbs 200100 bytes configures and displays ‟200100 bytes”.
For the 7705 SAR, 1 kbyte of buffer management space is 1000 bytes.
The MBS value in bytes is converted automatically to the number of buffers. The conversion calculation uses a non-configurable buffer size of 2304 bytes or 512 bytes, depending on the type of adapter card. See Table: Buffer Support on Adapter Cards and Platforms for a list of adapter cards and their associated buffers. The calculation is:
Number of buffers = Configured MBS value in bytes / Buffer size in bytes (2304 or 512)
At the egress of an N > 1 Apipe, the MBS value in a SAP egress QoS policy that is assigned to a SAP aggregation group is used for each of the per-SAP queues for SAPs that are members of a SAP aggregation group. See the show pools command for information about how to view buffer pools for SAPs that are members of a SAP aggregation group. See the 7705 SAR Services Guide for information about how to configure SAP aggregation groups.
The MBS value is used by a queue to determine whether it has exhausted all of its buffers while enqueuing packets. Once the queue has exceeded the amount of buffers allowed by MBS, all packets are discarded until packets have been drained from the queue.
The sum of the MBS for all queues on an adapter card can exceed the total amount of buffering available. Therefore, for a packet arriving at a queue that has not exceeded its MBS size, it is not guaranteed that a buffer will be available. If a buffer is not available, the packet will be discarded. RED/WRED slope parameters can be configured to control congestion in the case where the buffer capacity of the card is becoming exhausted.
Setting proper CBS parameters and controlling CBS oversubscription is one major safeguard against queue starvation (that is, when a queue does not receive its fair share of buffers). Another safeguard is to properly set the RED/WRED slope parameters for the needs of services on this port or channel.
The no form of this command returns the MBS size assigned to the queue to the default value.
180 (kbytes) (converted to 78 packets when buffer size is 2304 bytes and to 351 packets when buffer size is 512 bytes)
the size parameter is an integer expression of the maximum number of bytes of buffering allowed for the queue. A value of 4000 bytes or less causes the queue to discard all packets. Selecting default returns the MBS to the default value.
specifies that the size entered is in bytes
specifies that the size entered is in kbytes
rate pir-rate [cir cir-rate]
no rate
config>qos>sap-ingress>queue
config>qos>sap-egress>queue
This command defines the administrative PIR and the administrative CIR parameters for the queue. Defining a PIR does not necessarily guarantee that the queue can transmit at the intended rate. Similarly, defining a CIR does not necessarily guarantee that the queue can schedule at the intended rate. The actual rate sustained by the queue can be limited by oversubscription factors or available bandwidth.
The cir keyword defines the rate at which the system prioritizes the queue over other queues competing for the same bandwidth.
For service ingress, the PIR defines the maximum rate that the queue can transmit packets towards the fabric. The cir keyword defines the rate that packets are considered in-profile by the system. In-profile packets are preferentially queued by the system at egress and at subsequent next hop nodes where the packet can traverse. To be properly handled as in- or out-of-profile throughout the network, the packets must be marked accordingly for profiling at each hop.
For service egress queues, the PIR defines the maximum rate that the queue can transmit packets out an egress interface.
When the PIR is set to max on a SAP-ingress queue, the max value defaults to the physical port line rate. On a SAP-egress queue, the PIR is set to the physical port line rate.
The no form of the command returns all queues created with the queue-id by association with the QoS policy to the default PIR and CIR parameters (max, 0).
The rate command can be executed at any time but should be executed during a maintenance window because the command can be service-affecting. Altering the PIR and CIR rates affects all queues created through the association of the service ingress or service egress QoS policy with the queue-id.
The ingress traffic to an Epipe, Ipipe, IES, VPLS, and VPRN service may be shaped to a lower rate than the PIR and CIR values configured in the SAP ingress policy.
At SAP ingress, the CIR and PIR settings under rate include both payload (customer) traffic and overhead traffic, which affects the shaping rate internally. Additional overhead bytes include the internal fabric header minus any bytes that have been removed from the original packet (such as the four-byte FCS).
At SAP ingress, the actual shaping rate is related to the service rate (PIR or CIR) specified in the SAP ingress QoS policy, as shown below:
Shaping rate (actual) = (PIR or CIR) / ratio
where ratio = (customer packet size + additional bytes - removed headers - 4 byte FCS) / (customer packet size)
At SAP egress, shaping does not include the FCS, so the actual shaping rate is a bit higher than the PIR/CIR ratio configured in the QoS policy.
Shaping rate (actual) = (PIR or CIR) / ratio
where ratio = (customer packet size - 4 byte FCS) / (customer packet size)
rate max cir 0 (this default specifies the amount of bandwidth in kb/s. The max value and the pir-rate value are mutually exclusive.)
defines the administrative PIR rate, in kb/s, for the queue. When the rate command is executed, a valid PIR setting must be explicitly defined. When the rate command has not been executed, the default PIR of max is assumed. Fractional values are not allowed and must be given as a positive integer. The PIR rate has a minimum value of 8 kb/s.
The actual PIR rate is dependent on the queue’s adaptation-rule parameters and the actual hardware where the queue is provisioned.
overrides the default administrative CIR used by the queue. When the rate command is executed, a cir-rate setting is optional. When the rate command has not been executed or the cir keyword is not explicitly specified, the default CIR (0) is assumed. Fractional values are not allowed and must be given as a positive integer. The CIR rate has a minimum value of 8kb/s.
slope-policy name
no slope-policy
config>qos>sap-ingress queue
config>qos>sap-egress queue
This command specifies the slope parameters controlling the queue.
slope-policy default
the name of the slope policy