Unable to establish connection to remote Linux server

HI 

I am trying to setup the monitors for a remote Linux Server on Sitescope using Key Based Authentication.

I followed the Sitescope Using Sitescope- manual to set this up.However I get the error message Unknown Error (-1)

Sitescope version - 11.30

Below is the text from RunMonitor.log file

"" SSH internalConnectV2: A Connection error occurred: Key exchange failed: Failed to connect to server: Connection timed out: no further information (uc) dI <Failed to connect to server: Connection timed out: no further information> dI.notify false <null> wFKC.waited false true wFKC.done <false> connecting to host ""

I used RSA (ssh2) key

Please let me know what is the prob;lem here.

Thanks

Jagan Mohan.