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This module describes how to configure and apply Cisco IOS Performance Routing (PfR) cost policies. A PfR policy can be configured
to optimize traffic based on the monetary cost of the exit links. The PfR Cost Based Optimization feature provides financial
benefits by directing traffic to lower cost links, while at the same time honoring other configured policies such as delay,
loss, and utilization. Cost Based Optimization can be applied to links that are billed using a fixed or tiered billing method.
Load balancing based on cost can also be achieved.
Prerequisites for Performance Routing Cost Policies
Before implementing PfR cost policies, you need to understand an overview of how PfR works and how to set up PfR network
components. See the “Understanding Performance Routing,” “Configuring Basic Performance Routing,” and “Configuring Advanced
Performance Routing,” modules for more details.
Information About Performance Routing Cost Policies
To configure and apply PfR policies, you should understand the following concepts:
Overview of PfR Link Policies
PfR link policies are a set of rules that are applied against PfR-managed external links (an external link is an interface
on a border router on the network edge). Link policies define the desired performance characteristics of the links. Instead
of defining the performance of an individual traffic class entry that uses the link (as in traffic class performance policies),
link policies are concerned with the performance of the link as a whole. Link policies are applied both to exit (egress) links
and entrance (ingress) links. The following link policy types describe the different performance characteristics that can
be managed using link policies:
Traffic Load (Utilization) Policy
A traffic load (also referred to as utilization) policy consists of an upper threshold on the amount of traffic that a specific
link can carry. Cisco IOS XE PfR supports per traffic class load distribution. Every 20 seconds, by default, the border router
reports the link utilization to the master controller, after an external interface is configured for a border router. Both
exit link traffic and entrance link traffic load thresholds can be configured as a PfR policy. If the exit or entrance link
utilization is above the configured threshold, or the default threshold of 75-percent, the exit or entrance link is in an
out-of-policy (OOP) state and PfR starts the monitoring process to find an alternative link for the traffic class. The link
utilization threshold can be manually configured either as an absolute value in kilobytes per second (kbps) or as a percentage.
A load utilization policy for an individual interface is configured on the master controller under the border router configuration.
Tip
When configuring load distribution, we recommend that you set the interface load calculation on external interfaces to 30-second
intervals with the load-interval interface configuration command. The default calculation interval is 300 seconds. The load calculation is configured under
interface configuration mode on the border router. This configuration is not required, but it is recommended to allow Cisco
IOS XE PfR to respond as quickly as possible to load distribution issues.
A traffic load policy describes an upper limit for the traffic to be carried on a single link. For more details about configuring
a traffic load policy, see the Configuring an Exit Link Load Balancing PfR Policy: Example configuration example in the "Configuring Advanced Performance Routing" module.
Range Policy
A range policy is defined to maintain all links within a certain utilization range, relative to each other in order to ensure
that the traffic load is distributed. For example, if a network has multiple exit links, and there is no financial reason
to choose one link over another, the optimal choice is to provide an even load distribution across all links. The load-sharing
provided by traditional routing protocols is not always evenly distributed, because the load-sharing is flow-based rather
than performance- or policy-based. Cisco PfR range functionality allows you to configure PfR to maintain the traffic utilization
on a set of links within a certain percentage range of each other. If the difference between the links becomes too great,
PfR will attempt to bring the link back to an in-policy state by distributing traffic classes among the available links. The
master controller sets the maximum range utilization to 20 percent for all PfR-managed links by default, but the utilization
range can be configured using a maximum percentage value.
Both exit link and entrance link utilization ranges can be configured as a PfR policy.
Note
When configuring a range policy remember that 80 percent utilization of a serial link is very different from 80 percent utilization
of a GigabitEthernet link.
A range policy describes a method of load-balancing the traffic over multiple links. For more details about configuring a
range policy, see the Configuring an Exit Link Load Balancing PfR Policy: Example configuration example in the Configuring
Advanced Performance Routing module.
Cost Policy
PfR support for cost-based optimization was introduced in Cisco IOS XE Release 3.3S. Cost-based optimization allows you to
configure policies based on the monetary cost (ISP service level agreements [SLAs]) of each exit link in your network. To
implement PfR cost-based optimization the PfR master controller is configured to send traffic over exit links that provide
the most cost-effective bandwidth utilization, while still maintaining the desired performance characteristics. A cost policy
describes a method of load-balancing the traffic over multiple links.
Cost Policy Billing Models
PfR cost-based optimization supports two methods of billing: fixed-rate billing or tier-based billing.
Fixed-rate billing is used when the ISP bills one flat rate for a link regardless of bandwidth usage. If fixed-rate billing
only is configured on the exit links, all exits are considered equal with regard to cost-optimization and other policy parameters
(such as delay, loss, and utilization) are used to determine if the prefix or exit link is in-policy.
Tier-based billing is used when the ISP bills at a tiered rate based on the percentage of exit link utilization. Each cost
tier is configured separately with an associated monetary cost and a percentage of bandwidth utilization that activates the
tier is defined. The lowest cost tier for an exit using tier-based billing is charged each month regardless of the bandwidth
actually utilized. An allowance is made for bursting in the algorithm used to determine the tier-based billing. In this situation,
bursting is defined as short periods of high bandwidth usage that would be expensive under fixed-rate billing.
A fixed-rate billing is a set monthly fee regardless of utilization. Tier-based billing also incurs at least the lowest-tier
cost per month, but the final monthly tier-based billing charge is determined by the cost assigned to the tier that matches
the sustained monthly utilization.
Link Utilization Rollup Calculations
The first step in determining the billing fee for each exit link per month is to calculate the link utilization rollup values.
Link utilization rollup values are the averages of the link utilization readings taken at regular intervals (sampling period)
from the ingress and egress interfaces at the border routers for a given rollup period. For example, if a sampling period
was set to 60 minutes, and the rollup was set at 1440 minutes (24 hours), we would have 24 ingress and 24 egress link utilization
samples used for calculating the link utilization rollup. An average is taken for each set of ingress and egress samples from
that rollup period to get a link utilization rollup value for the ingress and egress links.
Monthly Sustained Utilization Calculation
After the link utilization rollup calculation is performed, the monthly sustained utilization is calculated, The specific
details of tier-based billing models vary by ISP. However, most ISPs use some variation of the following algorithm to calculate
what an enterprise should pay in a tiered billing plan:
Gather periodic measurements of egress and ingress traffic carried on the enterprise connection to the ISP network and aggregate
the measurements to generate a rollup value for a rollup period.
Calculate one or more rollup values per billing period.
Rank the rollup values for the billing period into a stack from the largest value to the smallest.
Discard the top default 5 percent (an absolute or percentage value can be configured, but 5 percent is the default) of the
rollup values from the stack to accommodate bursting. In this situation, bursting is defined as any bandwidth above the sustained
monthly utilization. The remaining rollup values are known as the 95th percentile high if the default 5% is discarded.
After the rollups with the highest utilization values (the top 5 percent in this case) are removed, apply the highest remaining
rollup value in the stack, referred to as the sustained Monthly Target Link Utilization (MTLU), to a tiered structure to determine
a tier associated with the rollup value.
Charge the customer based on a set cost associated with the identified tier.
Note
A billing policy must be configured and applied to links in order for the master controller to perform cost-based optimization.
The monthly sustained utilization rollup calculations can be configured to use one of the following three techniques:
Combined
Separate
Summed
In the following explanations of the sustained utilization calculation techniques, the discard value is configured as an
absolute value of 10. The default discard value is 5 percent.
Using the combined technique, the monthly sustained utilization calculation is based on a combination of the egress and ingress
rollup samples on a single sorted stack, the highest 10 rollup values are discarded, and the next highest rollup value is
the MTLU.
Using the separate technique, the egress and ingress rollup samples for a link are sorted into separate stacks and the highest
10 rollup values for each stack are discarded. The highest remaining rollup value of the two stacks is selected as the MTLU.
Using the summed technique the egress and ingress rollup samples are added together. The summed values of each rollup sample
are placed into one stack, the top 10 rollup values are discarded, leaving the next highest rollup value as the MTLU.
The following table displays an example of how the sustained monthly utilization is calculated using the separate technique.
In the table below the rollup values for a 30-day period are displayed in order from the highest bandwidth to the lowest bandwidth
for both the egress and ingress rollup values. The top 10 values (shown in italic) are discarded because the master controller
has been configured to discard this absolute number of rollups. The next highest rollup value remaining in the two stacks,
62 (shown in bold), is the sustained monthly utilization. The sustained monthly utilization is used to determine the tier
at which the customer is billed for bandwidth usage on that link for that billing period.
Table 1. Sustained Monthly Utilization Example Calculation
Egress Rollups
Ingress Rollups
Rollups are Sorted from Highest Bandwidth to Lowest Bandwidth in Billing Period
89
92
Discard the top 10 egress and ingress as configured as an absolute value (see numbers in italics).
80
84
71
82
70
80
65
78
65
75
51
73
50
84
49
82
49
80
45
62
After the discarded values. the next highest value is 62 and this becomes the
SustainedMonthlyUtilization
42
60
39
55
35
53
34
52
30
45
30
43
30
35
29
33
25
31
20
25
19
23
12
21
10
15
10
11
9
10
8
10
4
5
1
1
0
0
How to Configure Performance Routing Cost Policies
Configuring a PfR Cost-Based Policy
Perform this task to configure basic PfR cost-based optimization. Cost-based optimization is configured on a master controller
using the
cost-minimization command in PfR border exit interface configuration mode (under the external interface configuration). Cost-based optimization
supports tiered and fixed billing methods.
In this task, the configuration is performed on the master controller router and it assumes that the border routers are configured.
Tier-based billing is configured with three cost tiers and a nickname for the service provider is set to ISP1. The monthly
sustained utilization calculation technique is configured to use the sum technique and the last day of the billing cycle is
on the 30th day of the month with an offset of 3 hours to allow for a difference in time zones.
The
cost-minimization command contains many variations of keywords and arguments. Only one of the required keywords and its associated syntax can
be configured on one CLI line, but multiple instances of this command can be entered. Only the
fixed and
tier keywords are mutually exclusive within the configuration for each border router link. For details about the full syntax,
see the
Cisco IOS Performance Routing Command Reference.
Enters PfR-managed border router configuration mode to establish communication with a border router.
An IP address is configured to identify the border router.
The value for the
key-chain-name argument must match the key-chain name configured at the border router identified by the
ip-address argument.
Note
The
key-chain keyword and
key-chain-name argument must be entered when a border router is initially configured. However, this keyword is optional when reconfiguring
or adding configuration for this border router.
Router(config-pfr-mc-br-if)# cost-minimization sampling period 10 rollup 60
Specifies the sampling period in minutes.
The value that can be entered for the sampling period
minutes argument is a number from 1 to 1440.
Use the optional
rollupkeyword to specify that samples are rolled up at the interval specified for the
minutes argument. The value that can be entered for the rollup
minutes argument is a number from 1 to 1440. The minimum number that can be entered must be equal to or greater than the number that
is entered for the sampling period.
In this example, the time interval between sampling is set to 10 minutes. These samples are configured to be rolled up every
60 minutes.
Router(config-pfr-mc-br-if)# cost-minimization end day-of-month 30 offset 5:00
Configures the parameters used to configure the last day of the billing cycle.
Use the optional
offsetkeyword to adjust the end of the cycle to compensate for a service provider in a different zone from UTC. The optional “-” keyword is used to allow for negative hours and minutes to be specified when the time zone is ahead of UTC.
In this example, the last day of the billing cycle is on the 30th day of the month with an offset of 5 hours added to UTC.
Configures a nonusage-based fixed cost billing cycle or a tier of a tier-based billing cycle.
The
fixedfee keywords and
cost argument are used to specify a fixed (nonusage-based) cost associated with an exit link.
The
percentage argument is used to specify the percentage of capacity utilization for a cost tier.
The
tierfee keywords and
fee argument are used to specify the fee associated with this tier.
In this example, the tier-based fee for 100 percent utilization is set to 1000.
Note
The first tier specified must be the 100 percent capacity utilization. Any following tier configurations must be for lesser
percentages and lower fees.
Step 11
Repeat Step 9 to configure additional tiers for a tier-based billing cycle.
--
Step 12
exit
Example:
Router(config-pfr-mc-br-if)# exit
Exits PfR border exit interface configuration mode and returns to PfR-managed border router configuration mode.
Configures a border router interface as a PfR controlled internal interface.
Internal interfaces are used for passive monitoring only. Internal interfaces do not forward traffic.
At least one internal interface must be configured on each border router.
Step 14
exit
Example:
Router(config-pfr-mc-br-if)# exit
Exits PfR border exit interface configuration mode and returns to PfR-managed border router configuration mode.
Step 15
Repeat Step 14 to return to PfR master controller configuration mode.
--
Step 16
Repeat from Step 4 to Step 15 to configure additional cost-based optimization policies for other links, if required.
--
Step 17
moderoutecontrol
Example:
Router(config-pfr-mc)# mode route control
Configures route control for matched traffic.
In control mode, the master controller analyzes monitored prefixes and implements changes based on policy parameters.
Step 18
resolvecostpriorityvalue
Example:
Router(config-pfr-mc)# resolve cost priority 1
Sets policy priority for cost policies.
The resolve policy configures cost policies to have the highest priority.
In this task, only one type of PfR policy is given priority. Be aware that other PfR policies are usually configured and
priorities must be carefully reviewed.
Step 19
end
Example:
Router(config-pfr-mc)# end
Exits PfR master controller configuration mode and returns to privileged EXEC mode.
Example:
The following example is just a sample configuration as shown in the task but with the added tiers to complete the tier-based
fee configuration. For a more complete example configuration of a basic PfR cost policy that includes both fixed-rate and
tier-based billing, see the Example: Configuring a Basic PfR Cost-Based Policy section.
Using a PfR Cost Policy to Minimize Billing and Load Balance Traffic
While basic PfR cost-based optimization can be useful, many organizations have multiple border router exit links and possibly
several different service providers charging different billing rates that increase according to the bandwidth utilized. In
this situation, some form of traffic load balancing across the links may be required in addition to the cost minimization
policy.
Perform this task on the master controller to configure a Performance Routing cost policy to minimize the monthly billing
charge for multiple border router exit links while load balancing traffic across the links. In this scenario, the network
has both fixed-rate and tier-based billing, and assuming that the customer is paying a monthly fee for the fixed-rate billing
and the pre-paid (lowest cost) tier of tier-based billing, PfR can perform traffic load balancing while optimizing for cost.
The figure below shows an example of how different billing rates can be defined for each link using bandwidth and cost parameters
that are defined through service level agreements (SLAs) that are identified as rules in the diagram. The main goal of this
task is to minimize the billing charge per exit link and to load balance traffic across the exit links. Although Link 1 may
be billed at a fixed-rate and Links 2 through 4 are subject to tier-based billing, all the links are set up as PfR tiers.
To accomplish the cost minimization the first rule is to utilize 80 percent of Link 1 and 30 percent of Links 2, 3 and 4,
as shown in the figure below. The second rule is to distribute additional traffic across Links 2, 3 and 4 to balance the traffic
load. To achieve the traffic load balancing while minimizing cost, the solution is to configure a PfR cost policy using multiple
tiers representing bandwidth percentages that are assigned artificial costs to ensure that the PfR traffic is optimized for
cost and load balanced across all the exits. To illustrate the configured tiers, see the figure below.
The steps in this task create a cost policy in which PfR is configured to direct traffic through any of the lowest cost exits
first; Link 1 at 10.1.1.1 and the pre-paid tier of the other three exits. When the pre-paid tier bandwidth at each link is
fully utilized, the software determines the next lowest incremental cost between the tiers at all the links. The incremental
cost of utilizing the next tier at Link 1 is $990. The incremental cost of utilizing the next tier at Link 2 is only $10.
PfR forwards traffic to the next lowest cost tier which is the blue bar representing 40 percent of the bandwidth at Link 2,
as shown in the figure below. The process continues to use cost to balance the load across Links 2, 3, and 4. This task illustrates
how the monthly billing rate per exit link is minimized by utilizing the pre-paid bandwidth at Links 1 though 4 first, and
then the traffic is effectively load balanced across Links 2, 3 and 4 by determining the lowest incremental cost between tiers.
In the following task steps, the exit link 10.1.1.1 is configured as a tier-based link although it is actually charged at
a fixed rate. If a fixed rate link is configured as a tier for load balancing, the monthly cost calculation will not reflect
the true cost for that link. Using this solution, the artificial costs assigned to the multiple tiers may affect the accuracy
of all the monthly cost calculations.
Only some of the configuration steps for this task scenario are shown in the summary and detailed steps, the full configuration
for the master controller is displayed in the Examples section shown after the detailed steps table.
Note
Disable the range and utilization policy priorities because they may conflict with this application of the cost-minimization
feature.
Note
Do not configure the
periodic(PfR) or the
setperiodic(PfR) command with a time interval to avoid system churn as the system tries to select the best exit link at specified intervals.
This command is disabled by default.
The
cost-minimization (PfR) command contains many variations of keywords and arguments. Only one of the required keywords and its associated syntax
can be configured on one CLI line, but multiple instances of this command can be entered. Only the
fixed and
tier keywords are mutually exclusive within the configuration for each border router link. For details about the full syntax,
see the
Cisco IOS Performance Routing Command Reference.
Enters PfR-managed border router configuration mode to establish communication with a border router.
An IP address is configured to identify the border router.
The value for the
key-chain-name argument must match the key-chain name configured at the border router identified by the
ip-address argument.
Note
The
key-chain keyword and
key-chain-name argument must be entered when a border router is initially configured. However, this keyword is optional when reconfiguring
or adding configuration for this border router.
Enters PfR border exit interface configuration mode to configure a border router interface as a PfR-managed external interface.
At least one external interface must be configured on each border router.
Configuring an interface as a PfR-managed external interface on a router enters PfR border exit interface configuration mode.
In this mode, you can configure maximum link utilization or cost-based optimization for the interface.
Configures a nickname for a border router interface within a cost-based optimization policy on a master controller.
In this example, the nickname label for the 10.1.1.1 border router link is 80-percent.
Step 7
cost-minimizationsummer-timestartend[offset]
Example:
Router(config-pfr-mc-br-if)# cost-minimization summer-time 2 Sunday March 02:00 1 Sunday November 02:00 60
Specifies the start and end dates and times for summer time (daylight savings).
The
start and
end arguments are used to specify the week number, day, month and time in hours and minutes (24 hour clock) that summertime starts
and ends.
The
offset argument allows for an offset in minutes from 1 to 120 to allow for up to two additional hours to be added in the spring
and subtracted in the fall.
In this example, summer time is configured to start the second week in March on a Sunday at 2 in the morning plus one hour,
and end on Sunday in the first week in November at 2 in the morning minus one hour.
Note
The
summer-time keyword configuration is only required once for each master controller.
Configures a nonusage-based fixed cost billing cycle or a tier of a tier-based billing cycle.
The
fixedfee keywords and
cost argument are used to specify a fixed (nonusage-based) cost associated with an exit link.
The
percentage argument is used to specify the percentage of capacity utilization for a cost tier.
The
tierfee keywords and
fee argument are used to specify the fee associated with this tier.
In this example, the tier-based fee for 100 percent utilization is set to 1000.
Note
The first tier specified must be the 100 percent capacity utilization. Any following tier configurations must be for lesser
percentages and lower fees. When setting up tiers for load balancing, the tiers must be incrementally larger from one tier
to the next tier on the same link in order for load balancing to work.
Step 9
Repeat Step 8 to configure additional tiers for a tier-based billing cycle.
Configures the number of samples that are removed for bursty link utilization when calculating the sustained monthly utilization
value.
The utilization samples are ordered from the highest to the lowest and the number or percentage configured using this command
removes the highest number or percentage from the list.
If the optional
daily keyword is entered, samples are analyzed and discarded on a daily basis. If the
daily keyword is not entered, by default the samples are analyzed and discarded on a monthly basis. At the end of the billing cycle,
monthly sustained usage is calculated by averaging daily sustained utilization.
Use the
absolute keyword to configure a set number of samples to be removed.
Use the
percentage keyword to configure a percentage number of samples to be removed.
If a sampling rollup is configured, the discard values also applies to the rollup.
In this example, the highest 5 percent of samples are removed when calculating the sustained monthly utilization value.
Step 11
exit
Example:
Router(config-pfr-mc-br-if)# exit
Exits PfR border exit interface configuration mode and returns to PfR-managed border router configuration mode.
Configures a border router interface as a PfR controlled internal interface.
Internal interfaces are used for passive monitoring only. Internal interfaces do not forward traffic.
At least one internal interface must be configured on each border router.
Step 13
exit
Example:
Router(config-pfr-mc-br-if)# exit
Exits PfR border exit interface configuration mode and returns to PfR-managed border router configuration mode.
Step 14
Repeat Step 13 to return to PfR master controller configuration mode.
--
Step 15
Repeat from Step 4 to Step 14 to configure additional cost-based optimization policies for other links, if required.
--
Step 16
moderoutecontrol
Example:
Router(config-pfr-mc)# mode route control
Configures route control for matched traffic.
In control mode, the master controller analyzes monitored prefixes and implements changes based on policy parameters.
Step 17
policy-rulesmap-name
Example:
Router(config-pfr-mc)# policy-rules cost_balance
Applies a configuration from a PfR map to a master controller configuration.
In this example, configuration from a PfR map named cost_balance is applied.
Step 18
exit
Example:
Router(config-pfr-mc)# exit
Exits PfR master controller configuration mode and returns to global configuration mode.
Step 19
pfr-mapmap-namesequence-number
Example:
Router(config)# pfr-map cost_balance 10
Enters PfR map configuration mode to configure a PfR map.
Step 20
matchpfrlearn{delay|
inside|
throughput}
Example:
Router(config-pfr-map)# match pfr learn throughput
Creates a match clause entry in a PfR map to match PfR learned prefixes.
Only a single match clause can be configured for each PfR map sequence.
In this example, a match clause entry is created to match traffic classes learned using the highest outbound throughput.
Step 21
setresolvecostpriorityvalue
Example:
Router(config-pfr-map)# set resolve cost priority 1
Creates a set clause entry in an PfR map to set policy priority for overlapping policies.
In this example, the resolve policy configures cost policies to have the highest priority.
In this task, only one type of PfR policy is given priority. Be aware that other PfR policies are usually configured and
priorities must be carefully reviewed.
Step 22
end
Example:
Router(config-pfr-mc)# end
Exits PfR master controller configuration mode and returns to privileged EXEC mode.
Example:
The following configuration example is a complete configuration for all the links controlled by the master controller in
the figure above the task steps. Note the set resolve cost priority 1 command in the PfR map titled cost_balance that is used
to ensure that cost is the first priority for this task. In contrast, the resolve range and resolve utilization commands are
disabled to avoid optimization conflicts. For output from associated
show commands see the "Verifying and Debugging PfR Cost-Minimization Policies" section.
Verifying and Debugging PfR Cost-Minimization Policies
Perform this task on a master controller to display information to verify any cost-minimization policies and to help debug
any issues. After cost-minimization policies are configured and applied to traffic the
show command steps allow you to verify that the policy configuration is working as expected. If not, the
debug command steps can help troubleshoot any issues. The
show and
debug commands are all optional and can be entered in any order.
Before you begin
A cost policy must be configured and applied to PfR traffic before performing any of these steps.
Both the
border and the
nickname keywords of the
showpfrmastercost-minimization command display the same cost-minimization information. The keywords and arguments can be used to identify a specified border
router by its nickname or by an IP address and, optionally, for a specific interface on the router. Only the syntax applicable
to this step is shown. For the full syntax, see the
Cisco IOS Performance Routing Command Reference.
In this example, the information is displayed about the 10.2.1.2 link from the figure above. Note the number of cost tiers
configured for this link. The links at 10.3.1.3 and 10.4.1.4 have the same set of cost tiers to allow more precise load balancing.
There is information about the rollup values and parameters set for the discard values shown as an absolute value of 5. For
more details about the fields shown in this output, refer to the
Cisco IOS Performance Routing Command Reference.
This command is used to display the billing information for the previous billing period. In this example, the monthly sustained
utilization is 62 and the cost is $10,000 for the GigabitEthernet interface 3/0/0 link on border router 10.1.1.1.
Example:
Router# show pfr master cost-minimization billing-history
Billing History for the past three months
ISP2 on 10.4.1.4 Gi4/0/0
No cost min on 10.2.1.2 Gi3/2/0
ISP1 on 10.1.1.1 Gi3/0/0
Mon1 Mon2 Mon3
Nickname SustUtil Cost SustUtil Cost SustUtil Cost
---------- ------------------ ------------------ ------------------
ISP2 0 3000 ---NA--- ---NA---
ISP1 62 10000 ---NA--- ---NA---
---------- ------------------ ------------------ ------------------
Total Cost 13000 0 0
Step 4
debugpfrmastercost-minimization[detail]
This command is used to display debugging information for cost-minimization policies. The following example displays detailed
cost-minimization policy debug information.
Example:
Router# debug pfr master cost-minimization detail
OER Master cost-minimization Detail debugging is on
*May 14 00:38:48.839: OER MC COST: Momentary target utilization for exit 10.2.1.2 i/f
GigabitEthernet3/2/0 nickname ISP1 is 7500 kbps, time_left 52889 secs, cumulative 16 kb,
rollup period 84000 secs, rollup target 6000 kbps, bw_capacity 10000 kbps
*May 14 00:38:48.839: OER MC COST: Cost OOP check for border 10.2.1.2, current util: 0
target util: 7500 kbps
*May 14 00:39:00.199: OER MC COST: ISP1 calc separate rollup ended at 55 ingress Kbps
*May 14 00:39:00.199: OER MC COST: ISP1 calc separate rollup ended at 55 egress bytes
*May 14 00:39:00.199: OER MC COST: Target utilization for nickname ISP1 set to 6000,
rollups elapsed 4, rollups left 24
*May 14 00:39:00.271: OER MC COST: Momentary target utilization for exit 10.2.1.2 i/f
GigabitEthernet3/2/0 nickname ISP1 is 7500 kbps, time_left 52878 secs, cumulative 0 kb,
rollup period 84000 secs, rollup target 6000 kbps, bw_capacity 10000 kbps
*May 14 00:39:00.271: OER MC COST: Cost OOP check for border 10.2.1.2, current util: 0
target util: 7500 kbps
Configuration Examples for Performance Routing Cost Policies
Example Configuring a PfR Cost-Based Policy
The following example shows how to configure cost-based optimization on a master controller. Cost optimization configuration
is applied under the external interface configuration. In this example, a policy is configured for multiple exits with a tiered
billing cycle for one exit interface on border router 10.2.1.2 and a fixed fee billing cycle for the other exit interface
on border router 10.2.1.2 and both exit interfaces on border router 10.3.1.3.
In this scenario, PfR sends traffic first through the fixed-rate exits, GigabitEthernet interface 0/0/2 at border router
10.2.1.2 and GigabitEthernet interfaces 0/0/3 and 0/0/4 at border router 10.3.1.3, because the bandwidth cost is lower for
these fixed fee exits than the tier-based exit. When the fixed-rate exits are all fully utilized, the traffic is sent through
GigabitEthernet interface 0/0/0 on border router 10.2.1.2. If the monthly sustained utilization is 40 percent or lower, the
billing fee for the month will be $4000. If the monthly sustained utilization is higher then the tier that matches the monthly
sustained utilization is charged. In this example, no calculation configuration was entered and the default behavior is triggered;
the calculation is performed separately for egress and ingress samples.
This configuration example assumes that the border routers are already configured.
Example Using a PfR Cost Policy to Minimize Billing and Load Balance Traffic
The following configuration example shows how to configure cost-minimization policies and balance PfR traffic loads across
multiple links. This task is designed to minimize the cost of each link and to precisely control load balancing across multiple
border router links. This task controls the load balancing between multiple links by forcing PfR to use the bandwidth of the
lowest cost tier first and then use the next lowest cost tiers on all the links.
Keywords in the
showpfrmastercost-minimization command are used to view the utilization of a specific link with the monthly egress and ingress rollup values. After the
monthly billing period ends another keyword option for the billing history shows the sustained monthly utilization and link
cost.
Now enter the
showpfrmastercost-minimizationborder command at the master controller to show the configuration and the utilization statistics. The rollup values during the 30-day
March through April 24th billing period for the GigabitEthernet interface 3/0/0 on border router 10.1.1.1 are shown in the
output:
If we assume that the March through April 24th billing period is over, we can see the billing for the previous billing period
using the
showpfrmastercost-minimizationbilling-history command. The monthly sustained utilization is 62 and the cost is $10,000 for the GigabitEthernet interface 3/0/0 link on
border router 10.1.1.1.
Router# show pfr master cost-minimization billing-history
Billing History for the past three months
ISP2 on 10.4.1.4 Gi4/0/0
No cost min on 10.2.1.2 Gi3/2/0
ISP1 on 10.1.1.1 Gi3/0/0
Mon1 Mon2 Mon3
Nickname SustUtil Cost SustUtil Cost SustUtil Cost
---------- ------------------ ------------------ ------------------
ISP2 0 3000 ---NA--- ---NA---
ISP1 62 10000 ---NA--- ---NA---
---------- ------------------ ------------------ ------------------
Total Cost 13000 0 0
The Cisco Support and Documentation website provides online resources to download documentation, software, and tools. Use
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Feature Information for Configuring Performance Routing Cost Policies
The following table provides release information about the feature or features described in this module. This table lists
only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise,
subsequent releases of that software release train also support that feature.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco
Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Table 2. Feature Information for Configuring Performance Routing Cost Policies
Feature Name
Releases
Feature Configuration Information
OER Support for Cost-Based Optimization
Cisco IOS XE Release 3.3S
The OER Support for Cost-Based Optimization feature introduced the capability to configure exit link policies based monetary
cost and the capability to configure traceroute probes to determine prefix characteristics on a hop-by-hop basis.
The following commands were introduced or modified by this feature:
cost-minimization(PfR),
debugpfrmastercost-minimization,showpfrmastercost-minimization.