Hi, Ben,
As far as I know, most people who want extension validation either:
1. Dedicate one or two digits on the main IVR to extension dialing, and have all company extensions start with one of those digits. So, option 1 might be transfer to Sales, 2 and 3 would be extension dialing actions, 4 transfer to a sub-menu for customer service, 5 transfer to support, etc. That way if someone dials an invalid extension that begins with 2 or 3 they will hear the invalid extension prompt. If they dial something that starts with one of the other main menu options it will go to that option, since you do not have Listen for Extension Dialing turned on for the menu. This method, obviously, takes up two of the IVR positions but it gives you the feedback for an invalid extension.
2. Other folks designate one number on the main menu to access a sub-menu which has 1-9 set up as Dial by Extension actions. The main menu says, "To dial an extension, press one" and at the next menu "Please dial your party's extension". That will give feedback for an invalid extension no matter what number they start with (except zero). The down-side to this option is having to press an option first before dialing the extension.
So, those are the two main methods people use if they want invalid extension feedback.
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George Ganahl CCXP, GCP
Principal Technology Consultant
Genesys
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