This documentation is archived and is not being maintained.


This content is no longer actively maintained. It is provided as is, for anyone who may still be using these technologies, with no warranties or claims of accuracy with regard to the most recent product version or service release.

Enumerates available authentication modes used for signing in an endpoint into an Office Communications Server host.

Namespace: Microsoft.Office.Interop.UccApi
Assembly: Microsoft.Office.Interop.UccApi (in


Member nameDescription
UCCAM_BASICA flag indicating that the HTTP Basic Authentication scheme is needed or used with credentials consisting of a user name and password in plain text transmitted over the network. This authentication mode is not supported by Office Communicator. It is included for MSN compatibility.
UCCAM_DIGESTA flag indicating that the HTTP Digest access authentication is needed or used. The scheme is based on the Basic Authentication scheme but without sending a password in plain text over the network.
UCCAM_KERBEROSA flag indicating that the Kerberos authentication protocol is used for mutual authentication between a client and a server.
UCCAM_NONEA flag indicating that no authentication is needed or used.
UCCAM_NTLMA flag indicating that the NTLM authentication protocol is used requiring a challenge-response sequence with three messages being exchanged between a client and a server.

In signing in an endpoint into the server an application can use a member or a bit-wise combination of some members of this enumeration type to explicitly set allowed authentication modes. When a combination of all authentication modes are set as the value of the AllowedAuthenticationModes property on an IUccServerSignalingSettings instance the UCC API always selects the highest commonly supported authentication protocol. When the authentication fails, the application is responsible for handling the fallback. This often amounts to retrying with other not yet used authentication modes. An example is that an application retries the authentication process by setting the allowed authentication modes to UCCAM_DIGEST | UCCAM_NTLM & ~UCCAM_KERBEROS when the use of the Kerberos protocol fails.

Win32 COM/C++ Syntax

   UCCAM_NONE = 0x00000000,
   UCCAM_BASIC = 0x00000001,
   UCCAM_DIGEST = 0x00000002,
   UCCAM_NTLM = 0x00000004,
   UCCAM_KERBEROS = 0x00000008

Development Platforms

Windows XP Professional with Service Pack 2 (SP2), Windows Server 2000 with Service Pack 4, Windows Server 2003, Windows Vista Ultimate Edition, Windows Vista Business Edition, Windows Vista Enterprise Edition

Target Platforms