Please be more specific in what you installed. Voipswitch makes many different software products. You're probably talking about their calling card systems, as though are popular targets for hackers, but it isn't possible to be sure.
I also see a lot of companies claiming to have hack proof Voipswitch installations, apparently the software is popular and targeted by hackers often.
Do you mean you would like help in securing your server?
You can try asking for help here whenever you have a problem, but the experience with Voipswitch software will probably be limited.