The GetScheme function returns the scheme associated with the SIP URI.
string GetScheme( string uri );
Returns the scheme as a string. Returns null if the requested data is not found or if the URI passed in is not a valid SIP URI in the form specified above. Live Communications Server 2003 applications that pass non-SIP URI strings to this function need to be modified to work properly with Office Communications Server 2007.
The scheme value occurs in a SIP URI before the hostname and is separated by a colon. For example, a URI with a "sip" scheme appears as "sip:email@example.com".