PortMon
When your data center has many critical servers running, and you have many network related applications that are so critical if they are down unexpectedly you really want to get notified asap and have your application administrators to bring them up asap.

So do you have a solution for that?
Here we have a solution when your company has a subscription to an email to sms gateway service.

With our PortMon, you can use web based interface to add, list, start service availability monitors for critical UNIX/Linux/Windows servers and TCP based services, and once the monitors started, you can click the "check status" menu item to see all the monitored service availabity info. And more: when a monitor for a service detects that service is down, it will send a simple clear email to the recipients defined in the monitor setup. In addition, the monitor will also send an email if the service recovered. And using the web interface, you can also set maintenance window for individual service or all services which use same IP address, so during that window, no email will be sent no matter those services are up or down.

You can setup a virtual machine running RHEL/X86, CENT OS/X86,  or SuSE Enterprise Linux/x86 to run the PortMon.

When your company has the email to sms gateway service, with PortMon, when a critical UNIX/Linux/Windows machine goes down or a critical Oracle listener goes down unexptedly, now your relevant people can get the notification within a minute or 2, and start to act on it, in stead of getting called from customers and still need to figure out which server is related and till then the relevant people get notified.

Please refer to the "How to use PortMon" under the "How To" menu for more details.