In Cisco Unity 4.x, a user is unable to call a pager to provide message notification. On Cisco Unity, a user can leave a test voicemail and have a cell phone called.
Before you can offer SMS (SMPP) message notifications to subscribers, you must set up Cisco Unity so that it can communicate with the SMS Center (SMSC) that is affiliated with the mobile messaging service provider(s) that your organization has contracted with to provide SMS messaging services.
When you have an account, the service provider sends you the information necessary to configure an application like Cisco Unity known as an External Short Message Entity (ESME) to use the SMPP protocol to send text messages to the SMPP server at the SMSC. Then you enter the information on the System > SMPP Provider page.
You can create as many SMPP providers as you need. The providers that you add are available to all subscribers to use for SMS (SMPP) message notifications unless you specify otherwise. Consider that the more SMS (SMPP) message notifications that Cisco Unity sends to subscriber devices, the higher the costs to your organization (depending on the account, service providers typically charge for each SMS message or group of messages). For this reason, you may want to restrict the use of this feature to a group of subscribers by assigning owner(s) to the SMPP provider(s) that you create.