How can I configure this SMS notification via kannel? Can anyone explain in or drop a link related with my problem.
Since kannel's smsbox module has an HTTP interface, you can get a shell script (or any other type of HTTP-capable command line scripting language) to call it via a URI. If you don't already have kannel set up and running and as it is a rather complex beast, personally I'd recommend smstools if you're running a package-managed Linux distro.
Either way, more details below:
Well, assuming you can send sms messages from the command line in Kannel, you can configure Nagios to run a command on notification, then pass the right stuff to Kannel.
That said, this might not be your best way. I have Nagios sending notifications over XMPP, aka IM. I have a custom account in Gtalk that it's logged into all the time. So it works with any XMPP service. On both my Android phone and any IM Client on my computer (even when I have a browser open on my Google home page or GMail), when something happens on a server, I get a notification within seconds. I can even ask it for more information, or if the Internet drops, I can see that it went off-line. I find it far better then SMS in every way.