Provide of cst waybills to the seller by purchaser?

Hi friends

Please can any body tell me that whether if we purchase any engineering items from the parties of  other states do we provide Waybills from our side.  Or the party has to enclose waybills from his side.  One of my friend's company providing CST waybills to the other party for procuring the engineering items from them.

With Regards

B.sreenivasa rao