Compression Control Protocol

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The Compression Control Protocol ( CCP ) is a network protocol and is used to negotiate the data compression between the connection partners within a point-to-point connection (PPP) . The specification of the CCP was published with RFC 1962 in June 1996 and is an IETF standard. Parts were revised with RFC 2153 in May 1997.

Data compression algorithm

The data compression algorithms are selected in the CCP option type field. B. STAC LZS (CCP Option 17, RFC 1974 ), MPPC (CCP Option 18, RFC 2118 ), V.42bis (CCP Option 20), BSD LZW (CCP Option 21)

Check mode

The data compression methods use data from the past, which are included in the compression and stored in a movable data window. In order to maintain the synchronization of the data windows between the connection partners, a check procedure ("History check mode") is negotiated. This can e.g. B. be "sequential" or "extending". Microsoft Windows uses the "extended" check mode.

Common CCP procedures are:

  • None: No compression.
  • STAC: CCP Option 17, Check mode: sequential.
  • MS-STAC: CCP Option 17, Check mode: Extended.
  • MPPC: CCP Option 18, Check mode: Extended.

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