This is about the cheapest easiest way to test an IVR application without VoIP and honestly, really with VoIP. If you are a go it alone style IVR developer assigned to do a one time application for a company this is such a cheap and easy answer to testing it is hard to get your head around.

Here is a phone switch that can be purchased on ebay basically for the price of postage.  You can mount it on the wall near your desk or just drop it next to your workstation on the floor.  It is silent when running and does not require any programming to get basic services.  Also, it is compatible with regular analog phones so it will work great with your analog ports in your IVR.

This is not a T1 test system.

As you can see, there are only 8 phone extensions and three trunk lines.  Yep, you can set it up to take outside calls for testing too.

The unit is called a Panasonic 308 and they made a whole lot of em.  They were great for little companies that just needed to share some phone lines.  Now they are great for real phone IVR testing for a single developer or a couple of developers working together.

Remember these are old technology, no VoIP.  Just simple phone testing of an IVR.

Even if you plan to deploy a system for both VoIP and PSTN I have noticed it is actually a little easier to test with a touch tone phone than using a phone emulator on my desktop.  Could just be me, I have made about a million test phone calls over the last 20 years.

One caviot of this phone system is that it does not provide loop current disconnect signaling.  Though this can also be a plus as it tests to make sure your application terminates in all locations of the even if the caller does not hang up.