Damage Shield Buff Duration?

[Vizax_Xaziv]

So what is the classic DS Buff duration? I know it's CONSIDERABLY longer than the 3 minutes currently on Blue, but does anyone know the actual Classic-era Duration?

I'm tryin to do some damage:mana calculations. With the absence caster twink gear for mana and especially melee twink gear for dps, I think damage shields are going to offer groups a very high level of efficiency that most would likely underestimate!