As of 2005[update], Ogg Vorbis bitrate peeling existed only as a concept as there was not yet an encoder capable of producing peelable datastreams Bounties - XiphWiki.
Such formats include MPEG-4 SLS (scalable to lossless), WavPack, DTS-HD Master Audio and OptimFROG DualStream.
If the dial-up connection is of higher quality, and maybe about 42 kbit/s is available, the server will automatically switch to the 32 kbit/s stream.
The obvious benefit is much smaller space on a server required by such a file.
The reason that it is not available in Ogg Vorbis is that current encoders do not organize the code-stream to have progressive accuracy, thus peelers cannot tell which data is more or less important.