ok, now there is a stupid idea, tell your customer during the bid process for a new system that the cost of ownership includes upgrading the software every quarter when the new release comes out, and by the way, you have to pay a tech for that.
Don't forget that , oh wait a minute those upgrades never cause any issues that require fixing, or work arounds that can add even more to the cost of ownership by having to pay the tech for all their time, and materials, forget I mentioned that one.
Also, would a maint contract from Avaya then have to include all of those upgrades as they become available as well? After all that is maint is it not?
Or better yet, leave the damb release where it is unless you have a feature set you need that is available as the final maint release of the series for a major feature set release. If it is not broke, upgrade it, and it will be, or is that don't fix it?