Currently we are looking into getting a software that we would like to have a single number that rings exclusively in in a certain location and then is escalated to other location members if the call is unanswered after x rings. in short, an ICD with voicemail support.
We currently have a CUCM [CM 4.1(3)sr3a] but our voicemail system is not of Cisco (other brand).
Now can someone pls. advise whats the best method and econimical too. And do we need additonal servers/hardware, versions, etc...