The Media Antitrombone feature employs the “C” line trigger to use a signaling loop to pass media directly between two endpoints. This technique supports bandwidth optimization since the
Media Antitrombone is similar to Direct Media method, but eliminates the dependency on X-DMI header to identify the direct media. Media Antitrombone instead uses SDP “C” line for the identification of the signaling loop. The following diagrams show a typical RTP pass-through (or transcoding) using media loop application, and then the same call flow using Media Antitrombone feature.