Two-Way Active Measurement Protocol (TWAMP) provides a standards-based method for measuring the round-trip IP performance (packet loss, delay and jitter) between two devices. TWAMP uses the methodology and architecture of One-Way Active Measurement Protocol (OWAMP) to define a way to measure two-way or round-trip metrics.
There are four logical entities in TWAMP:
the control-client
the session-sender
the server
the session-reflector
The control-client and session-sender are typically implemented in one physical device (the ‟client”) and the server and session-reflector in a second physical device (the ‟server”) with which the two-way measurements are being performed. The 7210 SAS acts as the server. The control-client and server establishes a TCP connection and exchange TWAMP-Control messages over this connection. When the control-client requires to start testing, the client communicates the test parameters to the server. If the server corresponds to conduct the described tests, the test begins as soon as the client sends a Start-Sessions message. As part of a test, the session sender sends a stream of UDP-based test packets to the session-reflector, and the session reflector responds to each received packet with a response UDP-based test packet. When the session-sender receives the response packets from the session-reflector, the information is used to calculate two-way delay, packet loss, and packet delay variation between the two devices.