Another option is the Viking FBI-1A
https://www.retrevo.com/s/Viking-FBI-1A-review-manual/id/20833ci061/t/1-2/We have used these for years and have not had any problems whatsoever.
Question: Why didn't you use the Paging Port/MOH port?? You're using up a Line Port---it really doesn't make that much difference---just curious.
Also: Make sure your customer is not hitting that page key before picking up the handset. That, for sure, will give you a squeel. Make sure the volume levels are in the mid rang on your phones (both speaker and handset)---sometimes customers want to crank it up to max level---that creates huge problems. Those handset mics are pretty sensitive. What;s the noise (db)level of the area of those phones that are getting a squeel?? If it's noisy at times, you may encounter problems with people hearing the caller.
The reason I'm asking, is because you seem to indicate that the squeeling was not a problem before the Allworx was installed.
