Created with Sketch. Created with Sketch.

Shop by Category

Avaya KSUs

Avaya Telephone System KSUs

The Key Service Unit (KSU) is the "brain" which consolidates business telephone features / optional cards, etc and controls every aspect of the system.

While KSU was once a more-specifc term, today it is used more generally to refer to any main system processor responsible for running the show.

With it's complicated history, Avaya phone systems cover a huge range of different systems and seemingly manufacturers. We are happy to offer a wide range of these Avaya / Lucent / AT&T phone systems for sale here including:

Make an Offer!

Finding a good deal on Office Telephone equipment might make your kids roll their eyes, but your thrifty grandmother will be proud when you tell her what a good deal you got with us.

We will consider any reasonable offer for any Avaya phone system equipment we have for sale... and will do whatever we can to price match a serious competitor.

If you find a better price, better terms or better anything else but want to give us an opportunity to earn your business, please contact us with the product you want to purchase, the quantity you are seeking and the per unit price you think is fair.

Avaya Telephone System KSU User Guides / Manuals

As of February 2018, we have been working hard to add product manuals to as many of our product pages as possible. Sometimes tracking down a manual from 1985 proves to be challenging, but if you need any help finding a manual for your Avaya KSU please contact us and we will do our best to help.

Sell to Us

We are always interested in buying Avaya office telephone and related equipment and under most circumstances will pay for shipping by sending you prepaid label(s). Please get in touch with a list of what you have to offer and we will get back to you as quickly as possible.

There are no products listed under this category.