Unable to connect to the Exchange server using HTTP/HTTPS protocol.

hi,
i try to connect microsoft exchange server, but it give me error
Unable to connect to the Exchange server using HTTP/HTTPS protocol.

my code is pasted below............

<!--- connection parameters --->
<cfparam name="user1" default="uHRH">
<cfparam name="user2" default="uHRH">
<cfparam name="password" default="uHRH">
<cfparam name="exchangeServerIP" default="192.168.0.1">

<cftry>

<!--- Open a connection to the exchange server by specifying the required user credentials --->
<cfexchangeConnection
action="open"
username ="#user1#"
password="#password#"
server="#exchangeServerIP#"
<!--- protocol = "http"--->
connection="conn1">
<cfoutput>Connection to exchange server "#exchangeServerIP#" established</cfoutput>

<!--- Close connection to exchange server --->
<CFExchangeConnection
action="close"
connection="conn1">
<cfoutput>Connection to exchange server "#exchangeServerIP#" terminated</cfoutput>

<!--- Error Information --->
<cfcatch type="any">
<cfoutput>#cfcatch.message#</cfoutput>
</cfcatch>

</cftry>

if any one know how to solve this error?