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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

Minimum supported client

Windows 2000 Professional [desktop apps only]

Minimum supported server

Windows 2000 Server [desktop apps only]

Header

Ras.h

See also

Remote Access Service (RAS) Overview

Remote Access Service Structures

RasGetProjectionInfo

RASPROJECTION

RASPPPLCP