Multilink and Callback Connections

For the first link in a multilink connection, the authentication service sets the RAS_EAP_FLAG_FIRST_LINK flag in the fFlags member of the PPP_EAP_INPUT structure. The authentication protocol can use the presence of this flag to determine whether to present a user interface specifically for the first link of a multilink connection.

If the connection is configured so that the server calls back the client computer, the RAS_EAP_FLAG_FIRST_LINK flag will not be set on the callback.

If the authentication protocol sets the fSaveConnectionData member of PPP_EAP_OUTPUT to TRUE, subsequent links in the multilink connection receive the new connection-specific data. In the case of user-specific data, however, the authentication protocol continues to get the original user-specific data even if it sets the fSaveUserData member of PPP_EAP_OUTPUT to TRUE.

The authentication protocol may use an interactive user interface to collect data for a particular link of a multilink connection. In this case, the authentication service makes the resulting data available to the authentication protocol during subsequent links. However, this data is never saved to persistent storage.