Operation Process of TWAMP Light

Related Concepts

TWAMP Light has three measurement modes: on-demand, proactive, and periodic proactive measurement.

• On-demand measurement works in a specified period after being started. It can be performed once or periodically in the specified period.
• Proactive measurement works continuously after being started to collect statistics.
• Periodic proactive measurement works continuously at a specified interval.

Operation Process

1. Establishing a TWAMP Light service

   Figure 1 Establishing a TWAMP Light service
   

   The Controller and Responder are deployed as shown in Figure 1.

   1. The Control-Client on the Controller creates a TWAMP Light test session, and the Controller is specified as the Session-Sender.
   2. The Responder is specified as the Session-Reflector.
   3. The Session-Sender on the Controller starts the test session, and the Controller sends TWAMP-Test packets to the Responder based on the configured packet sending rate and packet template.
   4. The Responder responds to the TWAMP test packets.

2. Collecting performance statistics

   TWAMP Light defines two types of TWAMP-Test packets: Test-request packets and Test-response packets.

   • Session-Sender test packets are sent from the Controller to the Responder.
   • Session-Reflector test packets are replied by the Responder to the Controller.
   Figure 2 TWAMP Light implementation
   

   In Figure 2, TWAMP-Test packets function as probes and carry the IP address and UDP port number that are predefined for the test session between the Controller and Responder. The Controller sends a TWAMP-Test packet to the Responder, and the Responder replies to it. The Controller collects TWAMP statistics. The performance measurement process is as follows:

   1. The Controller collects statistics about the two-way delay, jitter, and packet loss rate based on the sequence numbers and timestamps carried in TWAMP-Test packets.

   2. The Controller collects performance statistics based on TWAMP-Test packets and reports the statistics to the NMS. The NMS provides performance statistics for users.

      In different measurement modes, the controller reports statistics to the NMS as follows:

      • On-demand measurement: reports statistics to the NMS using SNMP (MIBs).
      • Proactive measurement: reports statistics to the NMS using Performance Monitoring (PM).
      • Periodic proactive measurement: reports statistics to the NMS using PM.