Outbound Trunks - Cyclic use of

Hi I am setting up a system which will have eventually 100+ extensions and 35 Trunks.

The reason i am having that many trunks is to do with the fair usage policy of the itsp.

What i would like to do is use each of the trunks in turn so the outgoing calls are evenly distributed accross the trunks.

This would be a nice feature to have as on our office system as well, we havevisdn30 with 12 channels. Our imcumbent telephone supplier has a habbit of ‘borrowing’ isdn channels which dont have any traffic on them. The first you know is when customers say the lines are engaged.

Any help would be appreciated.