Try avoid transcoding

Hello, in Gateway->media section I found the option “Try avoid transcoding”. What does this option do? I can’t find any explanation on docs.
Thank you

it will change order of codecs in SDP anwer to prevend transcoding.

ok, so is it a random try? It changes order randomly and if we have luck it finds the same codec as the originator?

Of course no. It changes codec order based on negotiated codecs order on other leg, to have same order on both legs.