2.2.1.2.70 PPP_CCP_INFO

 The PPP_CCP_INFO structure contains information that describes the results of a Compression Control Protocol (CCP) negotiation.

 typedef struct _PPP_CCP_INFO {
   DWORD dwError;
   DWORD dwCompressionAlgorithm;
   DWORD dwOptions;
   DWORD dwRemoteCompressionAlgorithm;
   DWORD dwRemoteOptions;
 } PPP_CCP_INFO;

dwError: Specifies an error if the negotiation were unsuccessful. Zero (0) indicates success.

dwCompressionAlgorithm: Specifies the compression algorithm used by the local computer. The following table shows the possible values for this member.

Value	Meaning
0x00000000	The local computer has not negotiated any compression algorithm.
RASCCPCA_MPPC 0x00000006	Microsoft Point-to-Point Compression (MPPC) Protocol.
RASCCPCA_STAC 0x00000005	STAC LZS data compression algorithm [RFC1974] option 4.

dwOptions: Specifies the compression options on the local computer. The following options are supported.

Value	Meaning
0x00000000	No additional compression options are available.
PPP_CCP_COMPRESSION 0x00000001	Compression without encryption.
PPP_CCP_HISTORYLESS 0x01000000	Microsoft Point-to-Point Encryption (MPPE) in stateless mode. The session key is changed after every packet. This mode improves performance on high-latency networks, or networks that experience significant packet loss.
PPP_CCP_ENCRYPTION40BIT 0x00000020	MPPE using 40-bit keys.
PPP_CCP_ENCRYPTION56BIT 0x00000080	MPPE using 56-bit keys.
PPP_CCP_ENCRYPTION128BIT 0x00000040	MPPE using 128-bit keys.

dwRemoteCompressionAlgorithm: Specifies the compression algorithm used by the remote computer. The following table shows the possible values for this member.

Value	Meaning
0x00000000	The remote computer has not negotiated any compression algorithm.
RASCCPCA_MPPC 0x00000006	MPPC Protocol.
RASCCPCA_STAC 0x00000005	STAC option 4.

dwRemoteOptions: Specifies the compression options on the remote computer. The following options are supported.

Value	Meaning
0x00000000	No additional compression options are available.
PPP_CCP_COMPRESSION 0x00000001	Compression without encryption.
PPP_CCP_HISTORYLESS 0x01000000	MPPE in stateless mode. The session key is changed after every packet. This mode improves performance on high-latency networks, or networks that experience significant packet loss.
PPP_CCP_ENCRYPTION40BIT 0x00000020	MPPE using 40-bit keys.
PPP_CCP_ENCRYPTION56BIT 0x00000080	MPPE using 56-bit keys.
PPP_CCP_ENCRYPTION128BIT 0x00000040	MPPE using 128-bit keys.