Manish,
Did you try device registration(Logon plugin) with this SMP server before for other apps ?
The default port for connection is 8080.(Port number can be changed during the SMP installation by administrators). Please check if you are using a different port than 8080 (default).
I hope you have made sure that the SMP server is running and made tried with HTTP(s).
Its a good test to check the connection from the browser of the SMP server first.
Regards
Virinchy