How does -Dserviio.socketBuffer=xxxxx option work

What does -Dserviio.socketBuffer option in the "Supported system properties" do and how is it configured?
I have referred to this before.
I understand it works for DLNA but not MediaBrowser access.
What does it buffer - index, audio files, etc.
I have one server set to 262140 (four times the basic) and another to 393216 (six times the basic).
What impact/benefit does it have for audio (including large hi-res files) or is it mainly for video file use.
What typical values could be used without wasting memory?
I cannot find any detailed guidance.
I have referred to this before.
I understand it works for DLNA but not MediaBrowser access.
What does it buffer - index, audio files, etc.
I have one server set to 262140 (four times the basic) and another to 393216 (six times the basic).
What impact/benefit does it have for audio (including large hi-res files) or is it mainly for video file use.
What typical values could be used without wasting memory?
I cannot find any detailed guidance.