RASPPPCCP

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

typedef  struct tagRASPPPCCP  {
  DWORD    dwSize;
  DWORD    dwError;
  DWORD    dwCompressionAlgorithm;
  DWORD    dwOptions;
  DWORD    dwServerCompressionAlgorithm;
  DWORD    dwServerOptions;
} RASPPPCCP;

Members

dwSize

Size of the RASPPPCCP structure. Ensure that this member contains the size of the structure before using the structure in a function call.

dwError

If the negotiation was unsuccessful, dwError contains the error that occurred.

dwCompressionAlgorithm

The compression algorithm in use by the client. The following table shows the possible values for this member.

Value	Meaning
RASCCPCA_MPPC	Microsoft Point to Point Compression (MPPC) Protocol (RFC 2118)
RASCCPCA_STAC	STAC option 4 (RFC 1974)

dwOptions

Specifies the compression options on the client. The following options are supported.

Option	Meaning
RASCCPO_Compression	Compression without encryption.
RASCCPO_HistoryLess	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.
RASCCPO_Encryption56bit	MPPE using 56 bit keys.
RASCCPO_Encryption40bit	MPPE using 40 bit keys.
RASCCPO_Encryption128bit	MPPE using 128 bit keys.

The last three options are used when a connection is made over Layer 2 Tunneling Protocol (L2TP), and the connection uses IPSec encryption.

dwServerCompressionAlgorithm

The compression algorithm in use by the server. The following table shows the possible values for this member.

Value	Meaning
RASCCPCA_MPPC	Microsoft Point to Point Compression (MPPC) Protocol
RASCCPCA_STAC	STAC option 4

dwServerOptions

Specifies the compression options on the server. The following options are supported.

Option	Meaning
RASCCPO_Compression	Compression without encryption.
RASCCPO_HistoryLess	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.
RASCCPO_Encryption56bit	MPPE using 56 bit keys.
RASCCPO_Encryption40bit	MPPE using 56 bit keys.
RASCCPO_Encryption128bit	MPPE using 56 bit keys.

The last three options are used when a connection is made over Layer 2 Tunneling Protocol (L2TP), and the connection uses IPSec encryption.

Requirements

  Windows NT/2000: Requires Windows 2000.
  Windows 95/98: Unsupported.
  Header: Declared in Ras.h.
  Unicode: Declared as Unicode and ANSI structures.

See Also

Remote Access Service (RAS) Overview, Remote Access Service Structures, RasGetProjectionInfo, RASPROJECTION, RASPPPLCP