This chapter describes commands that configure the Compression Control Protocol (CCP) layer. All of these commands apply to the currently active bundle.
To use CCP you should enable compression at the bundle level. To allow compression to be negotiated you should enable here some of compression protocols.
set ccp accept option ...
set ccp deny option ...
set ccp enable option ...
set ccp disable option ...
set ccp yes option ...
set ccp no option ...
These commands configure various CCP options. Each direction of
traffic (transmit and receive) is independent from the other.
All options default to
disable commands determine
whether we desire the corresponding option on received data.
deny commands determine
whether we will allow the peer to request the corresponding option
(which we must enable on our transmitted data).
yes command is the same as
no command is the same as
The options available at the CCP layer are listed below. Note that the STAC and MPPC options require proprietary files that are not included with the normal mpd distribution.
This option enables Predictor-1 (RFC 1978) compression. Predictor-1 compression is much faster then Deflate.
This option require ng_pred1 Netgraph node type, which is present since FreeBSD 6.2-STABLE of 2007-01-28. If there no ng_pred1 in system, this algorithm is supported in user-level, but will consume more CPU power. To reduce packet loss in user-level on fast links it is recommended to increase values of net.graph.recvspace and net.graph.maxdgram sysctl variables.
This option enables Deflate (RFC 1979) compression. Deflate compression usually gives better compression ratio then Predictor-1.
This option require ng_deflate Netgraph node type, which is present since FreeBSD 6.2-STABLE of 2007-01-28.
This option is required in order to enable the Microsoft Point-to-point compression (MPPC) and/or Microsoft Point-to-point encryption (MPPE) protocols. However, this option does not actually enable MPPC or MPPE; you must use additional options (below) for that.
This option is required because of the way Microsoft implemented MPPC and MPPE as additional, optional sub-components of the MPPC protocol.
Note: in order for MPPE to work, MS-CHAPv1 or MS-CHAPv2 is mandatory, because the MPPE keys are generated using the results from authentication.
Enables MPPC compression. This is the only compression method supported by Microsoft Windows RAS.
This option requires compression support from ng_mppc node which is usually disabled as it require some Hi/Fn proprietary files.
Enables 40-bit MPPE encryption.
Enables 56-bit MPPE encryption. Note: 56 bit MPPE encryption is only supported in FreeBSD 4.5 or later.
Enables 128-bit MPPE encryption.
Enables stateless mode. This mode requires more CPU time and is somewhat less secure, but allows faster recovery in the face of dropped packets.
If enabled, Mpd uses the MPPE-Types and MPPE-Policy info from the authentication backend.