MICS 6.1 xc, 3 T-1's, non-PRI.

This customer is a collection agency, so as you imagine, outbound traffic is high.
They intermittently get "no free lines"
even though they have 64 channels in Pool A (8 channels are in pool B for their legal dept.) This happens even when there's only 10 or 20 people in in the morning or on a Saturday.

The carrier says they have never hit ceiling.

We've troubleshot our balls off and can find nothing wrong in our system cofig.

My hunch (and tech support) says it's the carrier. They disagree.

What we have here, boys, is a Mexican stand-off.

The main reason I am second guessing myself is that in another post I made with a similar problem on a 3-PRI system it turned out to be CbC limits. That parameter is not available on a straight T-1.

Is there an equivilant parameter I am over-looking??

Punch down all your damn pairs!..........(please).