Using the Two-Way Active Measurement Protocol (TWAMP)

Use the Two-Way Active Measurement Protocol (TWAMP) to measure round-trip IP performance between any two TWAMP-enabled units deployed in a network. With TWAMP, you can reliably perform in-band, roundtrip performance measurements and identify performance issues by sending test packets to a unit that reflects them back.

With TWAMP packet generation, you can perform one- and two-way delay and delay variation in a Layer-3 network, and measure packet loss. The Cisco Provider Connectivity Assurance Sensor Control allows TWAMP packets to be reflected through its linked remote devices.

TWAMP defines two protocols:

• TWAMP control protocol
• TWAMP test protocol

TWAMP light only includes the test protocol and is supported by the remote devices’ TWAMP reflection feature. When using TWAMP light, test sessions can be configured without the control protocol.

Setting Up TWAMP Control Behavior

TWAMP control protocols include:

• Alarm indicating an issue with TWAMP control protocol:
  Error information is transferred to the result record if the user is disconnected from the twampcontrol server and a progress/state XML message is sent to sensor orchestration capabilities within Provider Connectivity Assurance (formerly Skylight orchestrator).

• TWAMP UDP data continues when TWAMP control protocol stops.

• On TWAMP session startup, the session goes into a waiting state if it cannot connect and keeps trying to establish the session.

• TWAMP packet loss alarm continues to be present even if the TWAMP control protocol is down.

▶ To enable this feature using the CLI, enter:

agent-server { disable }

pm-tools twamp-cp-continuous { enable }
pm-tools twamp-cp-continuous {show }
agent-server { enable }

Setting Up a TWAMP Reflector

The Sensor Control can be configured to reflect TWAMP packets through the remote devices linked to it. The following procedure shows how to enable this kind of packet reflection.

Displaying a Summary of TWAMP Sessions

▶ To display a summary of TWAMP sessions (stateless and stateful)

1. Access the page SOAM ▶ TWAMP ▶ Reflector ▶ Configuration.

   A list of all TWAMP reflection instances displays, divided into these sections: TWAMP Stateless summary, TWAMP Stateful default filter summary and TWAMP Stateful summary.

   See TWAMP Reflector Configuration Parameters for more information.

2. (Optional) Limit the view to only certain sessions. Pick from the options in the Filter dropdown list, enter a value, and then click Search.

   Tip: Enter an asterisk ( * ) as a wildcard to replace one or more characters.

Editing TWAMP Stateless Sessions

▶ To edit a TWAMP stateless session

1. In the Device column of TWAMP Stateless summary, click the session you want to edit.

   The TWAMP stateless configuration form displays.

2. Edit the fields as required, then click Apply.

   See TWAMP Reflector Configuration Parameters for more information.

Editing TWAMP Stateful Default Filters

▶ To edit a TWAMP Stateful default filter

1. In the Device column of TWAMP Statateful default filter summary, click the filter you want to edit.

   The TWAMP stateful default filter form displays.

2. Edit the fields as required, then click Apply.

   See TWAMP Reflector Configuration Parameters for more information.

Adding TWAMP Stateful Sessions

▶ To add a TWAMP stateful session

1. Click Add below TWAMP Stateful summary.

   The New TWAMP stateful configuration form displays.

2. Complete the parameters, then click Apply.

   See TWAMP Reflector Configuration Parameters for more information.

Editing TWAMP Stateful Sessions

▶ To edit a TWAMP stateful session

1. In the Session column of TWAMP Stateful summary, click the session you want to edit.

   The TWAMP Stateful configuration form displays.

2. Edit the fields as required, then click Apply.

   See TWAMP Reflector Configuration Parameters for more information.

Deleting TWAMP Stateful Sessions

▶ To delete a TWAMP stateful session

1. In the Session column of TWAMP Stateful summary, click the session you want to delete.

   The TWAMP Stateful configuration form displays.

2. Click Delete.

   See TWAMP Reflector Configuration Parameters for more information.

Configuring NFV TWAMP Stateful Reflections

▶ To configure NFV TWAMP stateful reflection

1. In the Session column of TWAMP Stateful summary, click the session you want to configure.

   The TWAMP Stateful configuration form displays.

   ---

   Note: The TWAMP session to be reflected in NFV must use a different UDP port than the TWAMP stateless reflection on the device and should not match any TWAMP stateful reflection filter on the device.

   ---

2. Enable the TWAMP reflection in sensor control.

   The UDP port used by the session to be reflected must match the UDP configured in (SOAM ▶ Software Generator/Reflector ▶ Reflector Configuration).

3. Click Apply.

   ---

   Note: To be reflected in NFV, the TWAMP session destination must be a VCE IP address.

   ---

   See TWAMP Reflector Configuration Parameters for more information.

TWAMP Reflector Configuration Parameters

TWAMP Configuration (SOAM ▶ TWAMP ▶ Reflector ▶ Configuration)

Managing In-Use Software Generators/Reflectors

Use the page SOAM ▶ Software Generator/Reflector ▶ Session Status to view details of current Actuator sessions, as well as a listing (or port map) of all ports associated with Actuator sessions that use Level-3 protocols (TCP, UDP).

The total number of sessions and reflectors in use, and the maximum number of each, appear at the top of the page.

Viewing the Status of Actuator Sessions

▶ To view the status of Actuator sessions

1. Access the page SOAM ▶ Software Generator/Reflector ▶ Session Status.

   A listing of all Actuator sessions, along with summary details, display.

2. (Optional) Limit the view to only certain sessions. Pick from the options in the Filter dropdown list, enter a value, and then click Search.

   Tip: Enter an asterisk ( * ) as a wildcard to replace one or more characters.

3. Click a Peer ID value from the list to view additional information such as the packet rate and bandwidth.

   See Actuator Session Parameters for information.

Actuator Session Parameters

Actuator Session Parameters (SOAM ▶ Software Generator/Reflector ▶ Session Status)

Viewing the Actuator Session Portmap

Knowledge of all ports currently in use by all Actuator sessions can be helpful when configuring with a firewall or when using sensor orchestration capabilities within Provider Connectivity Assurance’s auto-generate port feature to automatically assign port numbers.

▶ To view the Actuator session portmap

1. Access the page SOAM ▶ Software Generator/Reflector ▶ Session Status.

   A listing of all ports Actuator sessions displays in the Actuator Session Portmap section.

2. (Optional) Limit the view to only certain sessions. Pick from the options in the Filter dropdown list, enter a value, and then click Search.

   Tip: Enter an asterisk ( * ) as a wildcard to replace one or more characters.

   See Actuator Session Portmap Parameters for information.

Actuator Session Portmap Parameters

Actuator Session Portmap (SOAM ▶ Software Generator/Reflector ▶ Session Status)

Setting Up a Reflector

Use the page SOAM ▶ Software Generator/Reflector ▶ Reflector Configuration to view a reflector’s current status, to enable or disable reflectors, and to change a reflector's assigned port number.

• You can have up to two TWAMP UDP ports for reflectors on Sensor Control that have UDP/IPv4 and UDP/IPV6 encapsulation.
  This feature is fully-supported starting with Skylight Orchestrator 22.10. Using Skylight Orchestrator 22.07 or older requires the creation of a reflector object: create a reflector endpoint in Skylight Orchestrator using the IP address of the interface you want to use as a reflector, then create TWAMP reflector sessions for multiple TWAMP UDP ports with the previously-created reflector endpoint.
• Encapsulation methods udp/ipv6 and icmp/ipv6 are supported.

Configuring Reflectors

You can enable or disable a reflector and change its assigned port number.

▶ To configure a reflector

1. Access the page SOAM ▶ Software Generator/Reflector ▶ Reflector Configuration.

   A listing of all reflectors displays.

2. (Optional) Limit the view to only certain reflectors. Pick from the options in the Filter dropdown list, enter a value, and then click Search.

   Tip: Enter an asterisk ( * ) as a wildcard to replace one or more characters.

3. Click an Index value from the list.

   The Reflector Configuration form displays.

4. Complete the fields as required, then click Apply.

   See Reflector Configuration Parameters for information.

Reflector Configuration Parameters

Reflector Parameters (SOAM ▶ Software Generator/Reflector ▶ Reflector Configuration)

Reflector Status

Reflector Configuration

Viewing Software Generator/Reflector Session Statistics

Use the page SOAM ▶ Software Generator/Reflector ▶ Session Statistics to display state information and configuration details of running generator/reflector sessions.

▶ To view software generator/reflector session statistics

1. Access the page SOAM ▶ Software Generator/Reflector ▶ Session Statistics.

   Statistics for all generator/reflector sessions are provided in a grid.

   See Session Statistics Parameters for information.

2. (Optional) Limit the view to only certain Actuator sessions. Pick from the options in the Filter dropdown list, enter a value, and then click Search.

   Tip: Enter an asterisk ( * ) as a wildcard to replace one or more characters.

Session Statistics Parameters

Session Statistics (SOAM ▶ Software Generator/Reflector ▶ Session Statistics)