The PfR application interface feature defines the mode of communication and messaging between applications and the network for the purpose of optimizing the traffic associated with the applications. A provider is defined as an entity outside the network in which the router configured as a PfR master controller exists, for example, an ISP, or a branch office of the same company. The provider has one or more host devices running one or more applications that use the PfR application interface to communicate with a PfR master controller. A provider must be registered with a PfR master controller before an application on a host device can interface with PfR. Host devices in the provider network running an application that communicates with PfR must also be configured at a PfR master controller with an IP address and key chain password.

After registration, a host device in the provider network can initiate a session with a PfR master controller. When a provider application initiates a session with a PfR master controller, a session identifier (ID) number is allocated to the session. After a session is established, the application can send a request for reports containing performance numbers for traffic classes, dynamically create policies to influence the existing traffic classes, or specify new traffic class criteria.

The application interface can be used by Cisco partners to develop applications. An example of application developed by a partner is PfR Manager by Fluke Networks. PfR Manager is a complete graphical-user interface (GUI) interface for the Performance Routing technology. It provides detailed reporting on traffic class performance and PfR behavior as well as easy-to-use configuration of PfR traffic classes and policies. For more details about PfR Manager, go to http://www.flukenetworks.com.

The PfR application interface permits a maximum of five concurrent sessions, and keepalives are used to check that the session between the host application device and the PfR master controller is still active. If the session is dropped, all policies created in the session are dropped. An application may negotiate an ability for the session to persist in the case of a temporary outage.

The PfR application interface has three main levels of priority to help resolve conflicts with requests coming from providers, host devices, and policies. In the table below the three priority levels are shown with the scope of the priority, whether the priority level can be configured on the master controller, the range and default values, if applicable.

When multiple providers are registered with PfR, an optional priority value can be specified to give PfR the ability to order requests coming in from multiple providers. Host devices in a provider network can also be assigned a priority. The lower the priority value, the higher the priority. If you configure a priority, each provider must be assigned a different priority number. If you try to assign the same priority number to two different providers, an error message is displayed on the console. Host devices must also be configured with different priority numbers if a priority is configured. If a priority has not been configured for the provider or host device, the priority is set to the default value of 65535, which is the lowest priority.

The application administrator assigns a priority to all applications. This priority is conveyed to the Network in terms of a policy priority. The lower the application priority number, the higher the priority of the application. Policy priority is handled using the policy sequence number. A policy sequence number--see the table below--is a 64 bit number calculated by placing provider priority in bytes 1 and 2, host priority in bytes 3 and 4, policy priority in bytes 5 and 6 and Session ID in bytes 7 and 8. The policy sequence number is calculated by the PfR master controller. An example policy sequence number is 18446744069421203465, representing a provider priority value of 65535, a host priority of 65535, a policy priority of 101, and a session ID of 9.

Use the show pfr master policy command to view the policy sequence number. The lower the sequence number, the higher the priority for the policy.

In the situation where an application tries to create two policies with same policy priority; the second policy creation attempt will fail.

An application communicating through a PfR application interface can request performance reports from PfR and use the report information to create graphs and charts of the information. The figure below shows a diagram of an example reporting model. In this example, the topology contains multiple sites using PfR within the site. Each site has a master controller but the company wants to review reports about activities in each site such as overall inter-site traffic activity, voice and video traffic activity, and data center access reports. a PfR application interface solution is implemented with a reporting application--see the figure below--that resides in a central location. The reporting application is registered at each PfR master controller and the application initiates a session with each master controller and requests traffic class performance information. The master controller at each site exports information to the application, which consolidates the information and displays graphs and charts. Reports can be requested at specified intervals to keep the information on the reporting application updated.

Figure 1

PfR Application Interface Reporting Model

At each site the master controller can monitor provider activity. Several Cisco IOS command-line interface (CLI) commands allow you to view provider information including details about dynamic policies created by the application. Reporting can also be implemented for a single site.

In summary, the PfR application interface provides an automated method for networks to be aware of applications and provides application-aware performance routing.

1.    enable

2.    configure terminal

3.    pfr master

4.    api provider provider-id [priority value]

5.    host-address ip-address [key-chain key-chain-name] [priority value]

6.    Repeat Step 5 to configure additional host devices as required.

7.    end

• Troubleshooting Tips
  

1.    enable

2.    show pfr api provider [detail]

3.    show pfr master policy [sequence-number | policy-name | default | dynamic]

4.    show pfr master prefix [detail| inside[detail] | learned [delay| inside| throughput] | prefix [detail | policy| report| traceroute [exit-id | border-address | current] [now]]]

Router> enable

Router# show pfr api provider detail

API Version: Major 2, Minor 0
  Provider id 1001, priority 65535
   Host ip 10.3.3.3, priority 65535
    Session id 9, Version Major 2, Minor 0
    Num pfx created 2, Num policies created 2
    Last active connection time (sec) 00:00:01
    Policy ids : 101, 102,
   Host ip 10.3.3.4, priority 65535
    Session id 10, Version Major 2, Minor 0
    Num pfx created 1, Num policies created 1
    Last active connection time (sec) 00:00:03
    Policy ids : 103,
  Provider id 2001, priority 65535
   Host ip 172.19.198.57, priority 65535
    Session id 11, Version Major 2, Minor 0
    Num pfx created 0, Num policies created 0
    All Prefix report enabled
    All exit report enabled

Router# show pfr master policy dynamic

Dynamic Policies:
 
  proxy id 10.3.3.3
  sequence no. 18446744069421203465, provider id 1001, provider priority 65535
    host priority 65535, policy priority 101, Session id 9
  backoff 90 90 90
  delay relative 50
  holddown 90
  periodic 0
  probe frequency 56
  mode route control 
  mode monitor both
  mode select-exit good
  loss relative 10
  jitter threshold 20
  mos threshold 3.60 percent 30
  unreachable relative 50
  next-hop not set
  forwarding interface not set
  resolve delay priority 11 variance 20
  resolve utilization priority 12 variance 20
  proxy id 10.3.3.3
  sequence no. 18446744069421269001, provider id 1001, provider priority 65535
    host priority 65535, policy priority 102, Session id 9
  backoff 90 90 90
  delay relative 50
  holddown 90
  periodic 0
  probe frequency 56
  mode route control 
  mode monitor both
  mode select-exit good
  loss relative 10
  jitter threshold 20
  mos threshold 3.60 percent 30
  unreachable relative 50
  next-hop not set
  forwarding interface not set
  resolve delay priority 11 variance 20
  resolve utilization priority 12 variance 20
  proxy id 10.3.3.4
  sequence no. 18446744069421334538, provider id 1001, provider priority 65535
    host priority 65535, policy priority 103, Session id 10
  backoff 90 90 90
  delay relative 50
  holddown 90
  periodic 0
  probe frequency 56
  mode route control 
  mode monitor both
  mode select-exit good
  loss relative 10
  jitter threshold 20
  mos threshold 3.60 percent 30
  unreachable relative 50
  next-hop not set
  forwarding interface not set
  resolve delay priority 11 variance 20
  resolve utilization priority 12 variance 20

Router# show pfr master prefix 10.1.1.0/24 report
Prefix Performance Report Request
   Created by: Provider 1001, Host 10.3.3.3, Session 9
   Last report sent 3 minutes ago, context 589855, frequency 4 min
 
Prefix Performance Report Request
   Created by: Provider 1001, Host 10.3.3.4, Session 10
   Last report sent 1 minutes ago, context 655372, frequency 3 min
 
OER Prefix Statistics:
 Pas - Passive, Act - Active, S - Short term, L - Long term, Dly - Delay (ms),
 P - Percentage below threshold, Jit - Jitter (ms), 
 MOS - Mean Opinion Score
 Los - Packet Loss (packets-per-million), Un - Unreachable (flows-per-million),
 E - Egress, I - Ingress, Bw - Bandwidth (kbps), N - Not applicable
 U - unknown, * - uncontrolled, + - control more specific, @ - active probe all
 # - Prefix monitor mode is Special, & - Blackholed Prefix
 % - Force Next-Hop, ^ - Prefix is denied
 
Prefix                  State     Time Curr BR         CurrI/F         Protocol
                      PasSDly  PasLDly   PasSUn   PasLUn  PasSLos  PasLLos
                      ActSDly  ActLDly   ActSUn   ActLUn      EBw      IBw
                      ActSJit  ActPMOS  ActSLos  ActLLos
--------------------------------------------------------------------------------
10.1.1.0/24             INPOLICY        0 10.3.3.3        Et4/3           BGP     
                               N        N        N        N        N        N
                             138      145        0        0        N        N
                               N        N