This is supported in Abacus Software Release 6.10 and onwards. The feature is based on draft-ietf-mmusic-media-loopback-10. The protocol supported in Abacus is SIP and the media being tested is audio. This is an active quality of service testing. During the test, audio data is encoded in the Test Server and sent via RTP stream to the customer’s device. There the data is looped back to the Test Server. The received file is analyzed and rated. This feature requires the special handling in the signaling protocol as stipulated in the draft RFC.