RASPPPCCP structure

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

The RasGetProjectionInfo function returns a RASPPPCCP data structure when its rasprojection parameter has the value RASP_PppCcp.

Note  Supported on Windows 2000 or later.

Syntax

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

Members

• dwSize
  The size, in bytes, of the RASPPPCCP structure. This member must be set before it is used in a function call.

• dwError
  A value that specifies the result of the negotiation. A value of zero indicates success. A nonzero value indicates failure, and is the fatal error that occurred during the negotiation.

• 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
  A value that specifies the compression types available on the local client. The following types are supported:

  Value	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_Encryption40bit	MPPE compression using 40-bit keys.
  RASCCPO_Encryption56bit	MPPE compression using 56-bit keys.
  RASCCPO_Encryption128bit	MPPE compression 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
  A value that specifies the compression algorithm used by the remote server. The following algorithms are supported:

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

   

• dwServerOptions
  A value that specifies the compression types available on the remote server. The following types are supported:

  Value	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_Encryption40bit	MPPE compression using 40-bit keys.
  RASCCPO_Encryption56bit	MPPE compression using 56-bit keys.
  RASCCPO_Encryption128bit	MPPE compression 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.

Requirements

See also

Remote Access Service (RAS) Overview

Remote Access Service Structures

RasGetProjectionInfo

RASPROJECTION

RASPPPLCP